The Taxonomy and Conservation of Palaquium in Brunei

The taxonomy and conservation of Palaquium

in Brunei

F. Culverhouse

2013

Thesis submitted in partial fulfillment for the MSc in the Biodiversity and Taxonomy of Plants

Abstract

The genus Palaquium Blanco. represents over half the Sapotaceae species found in Brunei and is an important component of Brunei’s forests, growing in six of the seven major forest types. This thesis provides an updated checklist of Palaquium from Brunei and includes a new species record for Brunei. For the first time all but one Palaquium species found in Brunei now have herbarium specimens collected from Brunei cited. A taxonomic account for the 20 species of Palaquium found in Brunei is provided and includes a genus description, full species descriptions, distribution maps and a key to the species. All herbarium specimens collected from Brunei in the BRUN, E and K herbaria have been added to the PADME Sapotaceae data base and, where possible, these have been georeferenced and images of specimens added. Using the distribution data gathered and literature based information of forest threats in Brunei conservation assessments for all species have been produced using IUCN criteria and categories. Problems associated with the lack of material for some species and limited distribution data is discussed as is the importance of taxonomic expertise and clean distribution data for accurate and full species descriptions and conservation assessments.

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Acknowledgements

I would like to thank my supervisor Peter Wilkie, for your guidance, patience, and your infectious enthusiasm for the subject.

I am grateful to Dr Rahayu Sukri and Mr Joffre Haji Ali Ahmad for allowing me to visit the Brunei National Herbarium to see the Sapotaceae collection.

Thank you also to all the RBGE staff who have taught me so much this year. The training by Louis Ronse De Craene, David Harris and Zoe Goodwin was especially useful for this thesis.

Finally thanks to Mum for your encouragement, and to Mike for making all those long bus journeys.

Contents Title Page………………………………………………………………………………………i Acknowledgements……………………………………………………………………………ii Abstract………………………………………………………………………………….……iii Contents……………………………………………………………………………………….iv Figures list………………………………………………………………………………….….v

Chapter one 1. General introduction………………………………………………………………………...1

Chapter two 2. Geography and biodiversity of Brunei……………………………………………………...2 2.1. Introduction…………………………………………………………………………….....2 2.2. Administrative districts…………………………………………………………………...3 2.3. Geography………………………………………………………………………………...3 2.4. Soils……………………………………………………………………………………….3 2.5. Climate……………………………………………………………………………………4 2.6. Biodiversity……………………………………………………………………………….4 2.7. Endemics………………………………………………………………………………….5 2.8. Forests in Brunei………………………………………………………………………….5 2.9. Main forest types………………………………………………………………………….5

Chapter three 3. Sapotaceae taxonomy and morphology……………………………………………………..7 3.1. Introduction……………………………………………………………………………….7 3.2. Economic importance……………………………………………………………………..7 3.3. Sapotaceae in Malesia…………………………………………………………………….7 3.4. Palaquium………………………………………………………………………………...7 3.5. Palaquium in Brunei……………………………………………………………………...8 v

3.6. Palaquium morphology…………………………………………………………………...9 3.7. Methods used for taxonomic account……………………………………………………19 3.8. Vernacular names………………………………………………………………………..20

Chapter four 4. Revision of Palaquium in Brunei………………………………………………………….20 4.1. Genus description………………………………………………………………………..20 4.2. Key to Palaquium of Brunei…………………………………………………………….21 4.3. Species descriptions……………………………………………………………………..24 Palaquium calophyllum………………………………………………………………………24 Palaquium cochleariifolium…………………………………………………………………26 Palaquium dasyphyllum……………………………………………………………………...28 Palaquium decurrens………………………………………………………………………...30 Palaquium gutta………………………………………………………………………………32 Palaquium herveyi……………………………………………………………………………34 Palaquium leiocarpum……………………………………………………………………….36 Palaquium majas……………………………………………………………………………...38 Palaquium microphyllum…………………………………………………………………….40 Palaquium obtusifolium……………………………………………………………………...42 Palaquium pseudocuneatum…………………………………………………………………43 Palaquium pseudorostratum………………………………………………………………...45 Palaquium quercifolium……………………………………………………………………..47 Palaquium ridleyi……………………………………………………………………………..49 Palaquium rioense……………………………………………………………………………51 Palaquium rivulare…………………………………………………………………………...53 Palaquium rostratum…………………………………………………………………………55 Palaquium sericeum………………………………………………………………………….57 Palaquium stipulare………………………………………………………………………….59 Palaquium walsurifolium……………………………………………………………………61 vi

Chapter five 5. Conservation assessments for Palaquium of Brunei………………………………………63 5.1. Conservation issues in Brunei…………………………………………………………...63 5.2. Forest reserves…………………………………………………………………………...65 5.3. IUCN conservation assessments………………………………………………………...66 5.4. Distribution data…………………………………………………………………………67 5.5. Palaquium conservation assessments……………………………………………………68 Palaquium calophyllum………………………………………………………………………68 Palaquium cochleariifolium…………………………………………………………………69 Palaquium dasyphyllum……………………………………………………………………...71 Palaquium decurrens………………………………………………………………………...72 Palaquium gutta………………………………………………………………………………73 Palaquium herveyi……………………………………………………………………………75 Palaquium leiocarpum……………………………………………………………………….76 Palaquium majas……………………………………………………………………………...78 Palaquium microphyllum…………………………………………………………………….79 Palaquium obtusifolium……………………………………………………………………...80 Palaquium pseudocuneatum…………………………………………………………………82 Palaquium pseudorostratum………………………………………………………………...83 Palaquium quercifolium……………………………………………………………………..84 Palaquium ridleyi……………………………………………………………………………..86 Palaquium rioense……………………………………………………………………………87 Palaquium rivulare…………………………………………………………………………...88 Palaquium rostratum…………………………………………………………………………90 Palaquium sericeum………………………………………………………………………….91 Palaquium stipulare………………………………………………………………………….92 Palaquium walsurifolium……………………………………………………………………94

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Chapter six 6. Discussion…………………………………………………………………………………95 6.1. Checklists………………………………………………………………………………..95 6.2. Taxonomic account……………………………………………………………………...96 6.3. Palaquium morphology………………………………………………………………….96 6.4. Collection data for conservation assessments…………………………………………...96 6.4.1. Limitations of collection data…………………………………………………………97 6.4.2. Varying collecting densities…………………………………………………………...97 6.4.3. Misidentification………………………………………………………………………97 6.5. Benefits and limitations of digital specimens……………………………………………97 6.6. Future work……………………………………………………………………………...98 6.7. Conclusion……………………………………………………………………………….98

References…………………………………………………………………………………...99 Appendix…………………………………………………………………………………...102

Figures list

Fig. 1. Map of Borneo…………………………………………………………………………2 Fig. 2. Map of districts of Brunei……………………………………………………………...3 Fig. 3. Map of global diversity………………………………………………………………...4 Fig. 4. Map of forest types in Brunei………………………………………………………….5 Fig. 5. Map of Palaquium in Malesia………………………………………………………….8 Fig. 6. Persistent stipules of P.sericeum...... 10 Fig. 7. Adpressed hairs on lower surface of leaf……………………………………………..10 Fig. 8. Erect hairs on lower surface of P.majas leaf…………………………………………11 Fig. 9. Branch of P.cochleariifolium showing leaves clustered at tips of twigs …………….11 Fig. 10. Decurrent leaf base…………………………………………………………………..12 Fig. 11. Shortly decurrent leaf base…………………………………………………………..12 Fig. 12. Truncate leaf base, not decurrent……………………………………………………12 Fig. 13. Sub-truncate leaf base, not decurrent………………………………………………..12 viii

Fig. 14. Submarginal loops of brochidodromous secondary veins…………………………..13 Fig. 15. Secondary veins run alongside midrib before arching away………………………..14 Fig. 16. Transverse tertiary veins…………………………………………………………….14 Fig. 17. Transverse-reticulate tertiary veins………………………………………………….14 Fig. 18. Parallel tertiary veins………………………………………………………………..15 Fig. 19. Parallel-reticulate tertiary veins……………………………………………………..15 Fig. 20. Axillary inflorescence above leaf scar………………………………………………15 Fig. 21. Calyx………………………………………………………………………………..16 Fig. 22. Opened flower showing 12 stamens………………………………………………...17 Fig, 23. Cross-section of 6-locular ovary…………………………………………………….18 Fig. 24. Ovary indumentum………………………………………………………………….18 Fig. 25. P.cochleariifolium fruit……………………………………………………………...19 Fig. 26. Seed of P.rostratum showing scar covering about ½ seed surface………………….19 Fig. 27. Map of P.calophyllum collection locations across range……………………………25 Fig. 17. Map of P.cochleariifolium collection locations across range……………………….27 Fig. 28. Map of P.dasyphyllum collection locations across range…………………………...29 Fig. 29. Map of P.decurrens collection locations across range……………………………...31 Fig. 30. Map of P.gutta collection locations across range…………………………………...33 Fig. 31. Map of P.herveyi collection locations across range…………………………………35 Fig. 32. Map of P.leiocarpum collection locations across range…………………………….37 Fig. 33. Map of P.majas collection locations across range…………………………………..39 Fig. 34. Map of P.microphyllum collection locations across range………………………….41 Fig. 35. Map of P.obtusifolium collection locations across range…………………………...43 Fig. 36. Map of P.pseudocuneatum collection locations across range……………………….44 Fig. 37. Map of P.pseudorostratum collection locations across range………………………46 Fig. 28. Map of P.quercifolium collection locations across range…………………………...48 Fig. 39. Map of P.ridleyi collection locations across range………………………………….50 Fig. 40. Map of P.rioense collection locations across range…………………………………52 Fig. 41. Map of P.rivulare collection locations across range………………………………...54 Fig. 42. Map of P.rostratum collection locations across range………………………………56 Fig. 43. Map of P.sericeum collection locations across range……………………………….58 Fig. 44. Map of P.stipulare collection locations across range……………………………….60 ix

Fig. 45. Map of P.walsurifolium collection locations across range………………………….62 Fig. 46. Image of cleared peat swamp forest for pipelines in Belait district. ………………..64 Fig. 47. Image of changing land use at border with Sarawak………………………………..64 Fig. 48. Deforestation across Borneo 1950-2020…………………………………………….65 Fig. 49. Image showing protected forests in Brunei……………………………………….…66 Fig. 50. IUCN Red List categories…………………………………………………………...67 Fig. 51. Map of P.calophyllum collections showing EOO…………………………………..68 Fig. 52. Map of collection locations of P.calophyllum in Brunei……………………………69 Fig. 53. Map of P.cochleariifolium collections showing EOO………………………………70 Fig. 54. Map of collection locations of P.cochleariifolium in Brunei………………………..70 Fig. 55. Map of P.dasyphyllum collections showing EOO…………………………………..71 Fig. 56. Map of collection locations of P.dasyphyllum in Brunei……………………………72 Fig. 57. Map of P.decurrens collections showing EOO……………………………………..73 Fig. 58. Map of collection locations of P.decurrens in Brunei………………………………73 Fig. 59. Map of P.gutta collections showing EOO…………………………………………..74 Fig. 60. Map of collection locations of P.decurrens in Brunei………………………………75 Fig. 61. Map of P.herveyi collections showing EOO………………………………………..76 Fig. 62. Map of collection locations of P.herveyi in Brunei…………………………………76 Fig. 63. Map of P.leiocarpum collections showing EOO……………………………………77 Fig. 64. Map of collection locations of P.leiocarpum in Brunei……………………………..77 Fig. 65. Map of P.majas collections showing EOO………………………………………….78 Fig. 66. Map of collection locations of P.majas in Brunei…………………………………..79 Fig. 67. Map of P.microphyllum collections showing EOO…………………………………80 Fig. 68. Map of collection locations of P.microphyllum in Brunei…………………………..80 Fig. 69. Map of P.obtusifolium collections showing EOO…………………………………..81 Fig. 70. Map of collection locations of P.obtusifolium in Brunei……………………………81 Fig. 71. Map of P.pseudocuneatum collections showing EOO………………………………82 Fig. 72. Map of collection locations of P.pseudocuneatum in Brunei……………………….83 Fig. 73. Map of P.pseudorostratum collections showing EOO……………………………...84 Fig. 74. Map of collection locations of P.pseudorostratum in Brunei……………………….84 Fig. 75. Map of P.quercifolium collections showing EOO…………………………………..85 Fig. 76. Map of collection locations of P.quercifolium in Brunei……………………………85 x

Fig. 77. Map of P.ridleyi collections showing EOO…………………………………………86 Fig. 78. Map of collection locations of P.ridleyi in Brunei…………………………………..87 Fig. 79. Map of P.rioense collections showing EOO………………………………………..88 Fig. 80. Map of collection locations of P.rioense in Brunei…………………………………88 Fig. 81. Map of P.rivulare collections showing EOO……………………………………….89 Fig. 82. Map of collection locations of P.rivulare in Brunei………………………………...89 Fig. 83. Map of P.rostratum collections showing EOO……………………………………..90 Fig. 84. Map of collection locations of P.rostratum in Brunei………………………………91 Fig. 85. Map of P.sericeum collections showing EOO………………………………………92 Fig. 86. Map of collection locations of P.sericeum in Brunei………………………………..92 Fig. 87. Map of P.stipulare collections showing EOO………………………………………93 Fig. 88. Map of collection locations of P.stipulare in Brunei…………………………….….93 Fig. 89. Map of collection locations of P.walsurifolium in Brunei…………………………..94 Fig. 90. Map of P.walsurifolium collections showing EOO…………………………………95

Chapter one

1. General introduction

Sapotaceae is a large pantropical family of about 1200 species (Govaerts, 2001). It consists predominantly of trees, with one liana and two woody geophytes (Pennington, 1991). Sapotaceae is placed in the order Ericales (APG III, 2009), and has long been recognised as a natural family with characters such as white exudate, spirally arranged leaves often clustered at the tips of twigs and a persistent calyx. Sapotaceae is an important component of wet lowland forest, and are also found with adaptations in semi-arid zones (Pennington, 1991) and in montane forest (Wilkie, 2011).

Aside from their ecological importance, many species of Sapotaceae have great economic significance. The timber of certain Madhuca Ham. ex J.F.Gmel. and Palaquium Blanco.species is highly valued for its durability and is widely used (commonly known as 'nyatoh' or 'bitis'). The latex of Palaquium gutta (Hook) Baill. has an important use today in dentistry, and was of great ecomonic significance historically with its elastic and insulating properties (Burkill, 1966). The latex of Manilkara zapota (L.) P.Royen. is used for chewing gum ('chicle'), and the species is cultivated for its edible fruit ('sapodilla') (Armstrong, 2011).

Taxonomic accounts have been produced for various genera in the Sapotaceae in the Malesian region (e.g. Lam, 1925; Jeuken, 1952; Assem, 1953; Vink, 1958; van Royen 1960) but these need updating to take into account new collections and new phylogenetic information. The most recent floristic account of Sapotaceae is for Sabah and Sarawak (Chai & Yii, 2002). No account of Sapotaceae has been published for Brunei. Palaquium is the most species rich genus of Sapotaceae in Malesia with c. 120 species (Govaerts, 2001), and according to

A Checklist of the Flowering Plants and Gymnosperms of Brunei Darussalam was published in 1996 (Coode et al, 1996) and is the most up to date list of species occurring in Brunei. In this Brunei was recognised as having six genera and 38 species of Sapotaceae. The most species rich genus, Palaquium, has 19 species. This thesis will update the checklist of Palaquium species found in Brunei and will provide full species descriptions and distribution maps for each species.

In 2010 in Nagoya, Japan 192 countries around the world adopted The Strategic Plan for Biodiversity 2011-2020 and the Aichi Biodiversity Targets (Aichi, 2010). It also adopted The Global Strategy for Plant Conservation (GSPC, 2010). These included a set of targets to help protect biodiversity. Target 2 of the GSPC was to have assessments of conservation status of all plants by 2020. Using the data gathered as part of the revision of Palaquium this thesis will present assessments for all species of Palaquium found in Brunei.

In summary the aims of this thesis are:

 To provide a taxonomic revision of Palaquium for Brunei

 To produce distribution maps for all Palaquium found in Brunei

 To make conservation assesments for all Palaquium in Brunei

 To highlight interesting morphology of Palaquium species

 To investigate the benefits and limitations of using digital images in

the production of taxonomic revisons

 To explore data limitations in producing conservation assesments

Chapter two

2. Geography and biodiversity of Brunei

2.1 Introduction

Brunei Darussalam (Brunei) lies 500 km north of the equator, in south-east Asia, between longitudes 114⁰ 23’ and 115⁰ 23’ E and latitudes 4⁰ and 5⁰05’N. Brunei is a small country in north-western Borneo, the second largest island in south-east Asia, at 725 000 km², and represents less than 1% of the island’s total land mass with an area of 5765 km². The island of Borneo is also composed of Indonesian Kalimantan, and Malaysian Sabah and Sarawak.

Fig. 1. Map of Borneo

2.2 Administrative Districts

Brunei has four administrative districts: Belait covering some 2696 km², Tutong covering 1152 km², Brunei-Muara covering 563 km² and Temburong covering 1288 km².

Fig. 2. Map of districts of Brunei (Image from d-maps.com) 2.3 Geography

Brunei’s 161 km coastline at the north of the country meets the South China Sea, all land borders are with neighbouring Sarawak. Four major rivers serve Brunei:

Sungai Belait (209 km) flows across Beleait district from it's source in the Labi Hills in south-eastern Belait; Sungai Tutong (137 km) has it's source close to Tutong district's eastern border with Sarawak; Sungai Temburong (98 km) begins in the mounains at the south of Ulu Temburong National park and Sungai Brunei's (48 km) source is near the village of Penkalan Batu in west Brunei-Muara district. To the north-east is a large natural bay with numerous small islands.

Brunei’s largest lake at 2500 ha is Tasek Merimbun, in the centre of Tutong district, its highest peak is Bukit Pagon at 1850m a.s.l, which lies at the south of Temburong district. The topology of much of Temburong district in eastern Brunei is mountainous with steep slopes and deep valleys (Sukri et al, 2012); to the west the districts of Belait, Tutong and Brunei- Muara consist of gentle hills and low lying land.

2.4 Soils

Alluvial soils are widespread in low lying and riverine regions of northern Belait, Tutong and Temburong districts. Shale and clay are the dominant substrates of southern Tutong and Temburong district. Temburong is also composed of hard sandstone ridge outcrops, while soft sandstone and clay is found in lower hill regions in the north and west of the country (Wong & Kamariah, 1999). Small pockets of white sand terraces occur in the districts of Belait, Tutong and Brunei-Muara. An area of thin limestone substrate is found in Belait district in the west of Brunei (Cranbrook & Edwards, 1994).

The most fertile soils are found in lowland clay soils, and non-peaty alluvial soils, whereas the least fertile soils are associated with the small pockets of white sand soils, and with the thin soils overlying the rugged sandstone terrain of Temburong (Loo et al, 1987).

2.5 Climate

The equatorial climate of Brunei is hot, humid and wet, with little variation in daylength (12 hours) during the year. Considerable variation is seen in the amount of rainfall across the country, with a gradient of decreasing precipitation from the furthest inland southern and south-eastern regions, which receive 4000 to 5000 mm per annum (Dykes, 2000), towards coastal areas which see 2000 to 3000 mm rainfall per annum (Cranbrook & Edwards, 1994). Rain falls all year round with only little differentiation between seasons, typically November is the wettest month, with slightly drier spells in January to February, and July to August (Poulsen et al, 1996). Temperatures also see little variation throughout the year with daytime temperatures regularly reaching 32⁰C and night time temperatures rarely falling below 20⁰C (Cranbrook & Edwards, 1994).

2.6 Biodiversity

South-east Asia is especially rich in biodiversity, and globally is the second highest region of species richness with ca. 25 000 species (Baas et al, 1989). Brunei is part of the Sundaland Hotspot, which covers the wetern half of the Indo-Malayan archipelago, one of 34 designated global hotspots for biodiversity (Conservation International, 2013). A Checklist of the Flowering Plants and Gymnosperms of Brunei Darussalam (Coode et al, 1996) lists 3451 species for Brunei with 1902 tree species. It has been estimated that the number could be closer to 5000 species of angiosperms, with 2000 tree species (Wong & Kamariah, 1999).

Borneo

Fig. 3. Map of global diversity (Kier et al., 2005)

2.7 Endemics

Borneo has the second highest endemic flora in Malesia with 989 endemic species, making up 36% of the island’s flora (van Welzen et al, 2011). It’s large island status, position west of Walllace’s Line, historical connection to mainland south-east Asia, its topographical range and everwet climate are all factors contributing to its rich endemic biodiversity.

Within Brunei there are currently thought to be 65 endemic species of angiosperms. Most are herbaceous belonging to families such as Begoniaceae and Gesneriaceae, although seven are trees belonging to the families Elaeocarpaceae, Menispermaceae, Myristicaceae, Polygalaceae and Rubiaceae (Henrot et al, 2013).

2.8 Forests in Brunei

Although widespread felling of forests has occurred throughout south-east Asia, Brunei is an exception, where only limited selective logging has been carried out (Ross & Dykes, 1996). Approximately 80% of land remains forested (Anderson & Marsden, 1984) around 70% of this is primary forest (Ross & Dykes, 1996) and 10% secondary forest. In comparison, widespread felling in Singapore has meant that less than 5% of its original forest cover remains (Sodhi et al, 2004).

Fig. 4. Map of forest types in Brunei (Image from presentation by Dr R.S. Sukri, ASEM workshop, May 2013)

2.9 Main Forest Types

Mixed dipterocarp forest covering 45.7% of the land area is the most widespread forest type in Brunei, and, as the name suggests is dominated by trees of Dipterocarpaceae. This family is the most species rich and widespread in Borneo with 267 species, 155 of which are

6 endemic to Borneo (Chung, 2013). Brunei has about 177 species of dipterocarps (Wong, 1999). They are an important component of many of the island's forests, and the most studied tree family in Borneo, the foremost publication is Peter Ashton’s ‘A manual of the Dipterocarp trees of Brunei State’ (Ashton, 1964). Characteristics of mixed dipterocarp forests are that no single species of dipterocarp is dominant, the canopy can reach 60 m and there is a sparse understorey. Non-dipterocarp families are often present within this forest type, but at much lower frequencies and include Sapotaceae. Much of Temburong district, Tutong district and lower Belait district are covered with mixed dipterocarp forest.

Peat swamp forest covers 18.2% of the land area. This forest type has a low and relatively even canopy compared with mixed dipterocarp forests, and trees of large diameter are infrequent. Adaptations include buttresses to withstand the unstable peat substrate, and pneumatophores to cope with the anaerobic conditions (Anderson, 1963). Trees of the peat swamp forest have tough coriaceous leaves with high lignin content, they decompose at a very slow rate, adding to the accumulation of peat which can gradually become domed to 20 m deep (Posa et al, 2011). The dipterocarp Shorea albida Symington. (commonly called Alan) is often the dominant tree species. The peat swamps of south-east Asia have global importance as a carbon sink. The most extensive peat-swamp forest in Brunei is found in northern Belait district.

Mangrove forest covers 4% of the land mass and is dominated by Rhizophora apiculata Blume., found mainly in the tidal, shallow, brackish water of Brunei Bay. Another species characteristic of this habitat is Nypa fruiticans Wurmb. (Arecaceae).

Freshwater swamp forest covers some 2.3% of the land mass and is found in low lying alluvial areas, the impervious clay substrate allows little drainage. Adaptations such as stilt roots and pneumatophores are frequently seen in swamp forest trees. The majority of freshwater swamp is in the low-lying land of Belait district where it follows the course of the Sungai Belait.

Kerangas or tropical heath forest covers 1.6% of the land mass. It has characteristically shorter, thinner trees with thicker leaves than other lowland tropical forests, species richness is also lower (Miyamoto et al, 2007). The white sandy soils are nutrient poor and acidic, vegetative adaptations to such conditions include the insectivorous Nepenthes spp.(L.) (Nepenthaceae) common at the margins of kerangas forests (Moran, 1996). Kerangas in Brunei is represented by small, fragmented patches of forest and is found in each of the four districts.

Montane forest covers 1.2% of the land mass and is the rarest forest type in Brunei. Elements of montane vegetation are found only in lower Temburong district. They differ from lowland forest in having a shorter canopy height and different species composition, with more Fagaceae and Myrtaceae and less Dipterocarpaceae (Pendry & Proctor, 1996).

(All forest cover percentages from Anderson & Marsden, 1984).

Chapter three

3. Sapotaceae taxonomy and morphology

3.1 Introduction

The pantropical family Sapotaceae mostly grows in lowland wet forest (Pennington, 1991), and can also occur at over 4000 m altitude (Wilkie, 2011). They are understory shrubs to emergent trees (Pennington, 1991). Characters uniting Sapotaceae include white exudate, simple spirally arranged leaves often clustered at the tips of twigs, flowers in fascicles, persistent calyx and style in fruit, and a distinctive scar on the seed surface (Wilkie, 2011).

Unique characters at genus level are rare in Sapotaceae, instead variations in sets of characters are used to define genera (Pennington, 1991). Issues at generic level were clarified by Pennington (1991) who recognised 53 genera. Previously this number fluctuated according to different authors with between 63 (Baehni, 1965) and 122 genera (Aubreville, 1964) being recognised. The species are considered generally well defined with around 1000 species currently recognised (WCSP, 2013).

Pennington (1991) recognises five tribes: Chrysophylleae, Isonandreae, Mimusopeae, Omphalocarpeae and Sideroxyleae. These are based on characters such as a uniseriate or biseriate calyx, stamen number relative to corolla lobes, and whether staminodes are present or not.

3.2 Economic importance

The latex of Palaquium gutta has historically been of major economic importance. It can be shaped on heating, becoming hard and retaining its shape when cool (Burkill, 1966). Uses have included the insulation of deep sea telegraph cables, and golf balls. Today the latex is still used in dentistry, with most other uses replaced by plastic. The major other economic uses of Sapotaceae is its timber and fruit.

3.3 Sapotaceae in Malesia

Pennington's The Genera of Sapotaceae (Pennington, 1991) covers the whole geographic range of the family, and is the most important recent work on the family. All five of Pennington's tribes occur in Malesia, with most represented by Isonandreae (Wilkie, 2011).

Lam (1925) estimated there to be 215 species of Sapotaceae in 15 genera in the Malayan region (today's Malesia), this figure rose to 261 species in van Royen's account (1960). Today the estimated number in Malesia is nearer 300 species (Wilkie, 2011).

3.4 Palaquium

The genus Palaquium was first described by Blanco in 1837, and belongs to the Isonandreae tribe, which groups seven genera that have a calyx with two whorls of lobes, entire corolla lobes, stamens 2-3 times more than the corolla lobes, and no staminodes (Govaerts, 2011).

Palaquium is the biggest genus of Sapotaceae in Malesia where it has its centre of diversity, representd by c. 119 species (Goevarts, 2001). The standard revision is the Revision of the Sapotaceae of the Malaysian Area in a Wider Sense (van Royen, 1960) which recognised 109 species of Palaquium, with 37 or 38 for Borneo (see Fig. 5.).

Fig. 5. Map of Palaquium in Malesia (van Royen, 1960) Van Royen (1960) recognised obovate leaves to be largely consistent for Palaquium and used exceptions from this to separate groups, such as those with spathulate leaves or elliptic to lanceolate leaves. Other characters used to divide the genus are tertiary veins, leaf size, indumentum, stamen number as well as geography. In total van Royen recognised seven groups 'without sharp distinction'.

Molecular phylogenetic studies do not generally support previous groupings based on morphology to be natural groups. Although recent work does group Palaquium microphyllum King & Gamble., P.rostratum (Miq.) Burck., and P.pseudorostratum H.J.Lam. which were in van Royen's Group 7 (Wilkie, unpubl.).

3.5 Palaquium in Brunei

Important publications relating to the Sapotaceae of Brunei are A Checklist of Brunei Trees (Hasan & Ashton, 1964) which lists ten species of Palaquium. Most recently A Checklist of the Flowering Plants and Gymnosperms of Brunei Darussalam (Coode et al, 1996) listed six genera of Sapotaceae and 19 species of Palaquium.

Publications for other regions of Borneo that are relevant to Brunei due to their close proximity include the Tree Flora of Sabah and Sarawak (Chai and Yii, 2002) which covers 41 Palaquium species. All of the Brunei species are included except P.obtusifolium. This species is not known in Sabah and Sarawak, but is present in Brunei and Central Kalimantan.

The Tree Flora of Malaya (Ng, 1972) contains 22 species of Palaquium, six of which are found in Brunei (P.gutta, P.herveyi King & Gamble., P.leiocarpum Boerl., P.microphyllum, P.ridleyi King & Gamble., P.rostratum).

Current work is being carried out at the Royal Botanic Garden Edinburgh to develop the Sapotaceae Resource Centre (www.sapotaceae.info), which facilitates access to Sapotaceae specimens and literature. It holds data on Brunei specimens from E, K, KEP, L, SAN, SAR and SING.

3.6 Palaquium morphology

The most useful morphological characters for distinguishing Palaquium species were found to be the leaf base, secondary veins, tertiary veins and indumentum. The number of stamens was also found to be taxonomically informative.

Bole and bark.

Of the 20 species found in Brunei 11 were recorded to have buttresses. Two, P.leiocarpum and P.walsurifolium Pierre ex Dubard., were recorded to have stilt roots and the remaining seven species had no record of buttressing or stilt roots. Due to the lack of consistent information on these characters they are not considered particularly taxonomically useful.

Bark may be smooth or fissured, although again this was not always recorded on labels and so its usefulness as a character was found to be limited for the purposes of this study.

Exudate

Exudate is always present. It may be fast or slow to appear, copious or not. At present there is not enough data on the speed and amount of latex produced to help distinguish species using these characters.

Twigs.

The diameter of twigs is found to be a useful character. P.decurrens H.J.Lam., has the largest diameter at 7--10 mm, resulting in a stouter appearance when compared with other species. Of the twenty Brunei species two are pachycaulis P.decurrens and P.stipulare Pierre ex Dubard. The smallest diameter twigs at 3 mm or less were seen in P.dasyphyllum Pierre ex Dubard., P.pseudocuneatum H.J.Lam., and P.sericeum H.J.Lam.

Stipules.

Stipules are mainly small and caducous and not particularly useful for species identification. However, the persistent stipule pairs of P.sericeum can aid identification.

Fig. 6. Persistent stipules of P.sericeum

Indumentum.

Hairs are typically adpressed. Simple, non-adpressed hairs are less common and a useful character for P.majas H.J.Lam. which has this hair type. P.sericeum is unusual with both types of hair present on the leaves. Presence or absence of hairs is generally consistent for adult leaves.

Fig. 7. Adpressed hairs on lower surface of leaf

Fig. 8. Erect hairs on lower surface of P.majas leaf Leaf arrangement.

Leaves are either well-spaced along twigs or clustered at the tips of twigs. Approximately half have well-spaced leaves and half clustered leaves although some species have both types of leaf arrangement (P.calophyllum Teijsm. & Binn., P.gutta and P.pseudocuneatum). This is a useful character, but sometimes difficult to distinguish on herbarium specimens where only the tips of twigs are present.

Fig. 9. Branch of P.cochleariifolium P.Royen showing leaves clustered at tips of twigs (Image by P.Wilkie)

Petiole.

The petiole on average is between 1--3.5 cm long. P.sericeum has the shortest petioles at 0.3- -0.7 cm long and P.quercifolium (de Vriese) Burck. the longest to 7 cm long (though not diagnostic for either species). The presence or absence of a groove or ridge on the upper petiole surface was initially thought to be taxonomically useful, but is now considered not to be.

Leaves.

All species have entire leaves, although sinuate margins were occasionally seen in P.majas and P.obtusifolium. Leaf shape can be used to group species, for example spathulate leaves are found in P.microphyllum, P.pseudocuneatum, P.pseudorostratum and P.rostratum, and oblanceolate leaves in P.decurrens, P.majas, P.sericeum and P.stipulare. It should be noted however that leaf shape can be highly variable as found in P.gutta.

Leaf size can be an important character with P.rivulare H.J.Lam having consistently large leaves (23--46 cm long) and P.microphyllum consistently small leaves (3--5 cm long). It was observed that leaves of young trees can be larger and more hairy.

The leaf base is typically found to be decurrent. The four species without a decurrent base can be separated by this character: P.majas (obtusely-attenuate base), P.rivulare (truncate- rounded base), P.sericeum (sub-cordate to truncate base) and P.stipulare (sub-cuneate to sub- cordate base).

Fig. 10. Decurrent leaf base Fig. 11. Shortly decurrent leaf base

Fig. 12. Truncate leaf base, not decurrent Fig. 13. Sub-truncate leaf base, not decurrent

The leaf apex is variable in many species and can be used to distinguish species. For example P.majas and has an acuminate tip and P.stipulare, a rounded or sub-emarginate apex.

Secondary veins.

The number of secondary vein pairs ranged from 20--30 in P.gutta to ≤10 in P.cochlearifolium, P.herveyi, P.ridleyi and P.walsuifolium. In P.gutta, P.pseudocuneatum, P.pseudorostratum, P.microphyllum it is possible to confuse secondary veins with parallel- tertiary veins.

Secondary veins are generally either eucamptodromous where veins do not reach the leaf margin, or brochidodromous with veins joined by submarginal loops. Most species are eucamptodromous. Brochidodromous venation is seen in P.gutta, P.leiocarpum, P.majas, P.microphyllum and P.rostratum. This is a useful character, although it can be sometimes difficult to differentiate between types. There are cases where loops are very faint and many eucamptodromous leaves have occasional loops espcially towards the leaf apex. I have tried to clarify this by highlighting in species descriptions where occasional loops are found in otherwise eucamptodromous species.

Fig. 14. Submarginal loops of brochidodromous secondary veins

The angle at which secondary veins emerge from the midrib is a useful character and can divide the Brunei species into three groups: veins consistently ≥70˚ (P.cochlearifolium, P.gutta, P.pseudorostratum and P.rostratum); veins ≤50˚ (P.calophyllum, P.dasyphyllum, P.herveyi, P.quercifolium and P.rostratum); and species with angles between these.

The apical part of the vein often runs alongside the midrib for about 1 mm before arching away. This may be a useful character to measure in future work.

Fig. 15. Secondary veins run alongside midrib before arching away

Tertiary veins.

Tertiary veins are useful and can be used to group species into four types: transverse (ladder- like) as seen in P.calophyllum, P.decurrens, P.herveyi, P.quercifolium, P.rivulare, P. sericeum and P.walsurifolium; parallel (running parallel to the secondary veins) seen in P.gutta and P.psedurostratum; transverse-reticulate as in P.cochleariifolium, P.dasyphyllum, P.leiocarpum, P.majas, P.obtusifolium Burck., P.ridleyi, P.rioense H.J.Lam. and P.stipulare; or parallel-reticulate found in P.microphyllum, P.pseudocuneatum and P.rostratum. If a leaf has more than one of these types, it is grouped by the dominant vein type.

Fig. 16. Transverse tertiary veins Fig. 17. Transverse-reticulate tertiary veins

Fig. 18. Parallel tertiary veins Fig. 19. Parallel-reticulate tertiary veins

Ng (1972) identifies four types of tertiary venation: descending (with two variations), transverse, reticulate and parallel-reticulate, whereas van Royen uses three distinctions transverse, parallel-ascending and reticulate. I found the terms descending and parallel ascending both confusing, and so chose to follow neither Ng's or van Royen's terms.

Inflorescence.

All inflorescences are axillary, except for P.cochleariifolium which may also have terminal inflorescences. Flower numbers are difficult to count, and a best estimate has been given in species descriptions.

Fig. 20. Axillary inflorescence above leaf scar

Pedicel.

Pedicel lengths varied from 2 to 35 mm long, with the average length c.10 mm long. P.cochleariifolium has the longest pedicel at 15--35 mm, it is also the only species with a glabrous pedicel.

Calyx.

The calyx is always in 2 whorls of 3 lobes. The outer and inner whorls of calyx lobes are frequently equal in length as found in P.cochleariifolium, P.dasyphyllum, P.decurrens, P.gutta, P.herveyi, P.leiocarpum, P.rivulare and P.walsurifolium. While for P.majas, P.rostratum and P.stipulare the inner whorl is longer. For P.quercifolium and P.pseudorostratum inner calyx lobe length is unknown. The remaining seven species have a longer outer calyx whorl.

The outer whorl margins are not scarious, fimbriate or glabrous, whereas this is a consistent inner whorl character. The outer whorl of lobes is usually densely hairy and the inner whorl sparser in comparison. Exceptions are P.ridleyi where the inner lobes are more hairy, and P.cochleariifolium where both whorls are glabrous.

Fig. 21. Calyx showing densely hairy outer whorl, and sparsely hairy inner whorl with glabrous margins

Corolla.

Corolla lengths vary from 2.5--20 mm long. P.decurrens and P.stipulare have the longest corollas at 20 mm long and P.microphyllum the shortest at 2.5--3 mm long. The average length is 5--10 mm long.

Another useful corolla character is whether the lobes are reflexed in anthesis or not. Five species have reflexed lobes: P.callophyllum, P.obtusifolium, P.pseudocuneatum, P.pseduorostratum and P.rostratum.

Stamens.

Stamen number is a useful character. In most species there is commonly 12 stamens, but variations are found in P.leiocarpum (9--12), P.majas (18), P.obtusifolium (12--18), P.pseudocuneatum (sometimes 8), P.rivulare (18-21) and P.stipulare (20).

For 10 of the 20 species the stamens are clearly arranged in two whorls (P.dasyphyllum, P.herveyi, Pmicrophyllum, P.pseudocuneatum, P.pseudorostratum, P.quercifolium, P.ridleyi, P.rioense, P.rostratum and P.walsurifolium). For the remaining species the stamens appeared to be in one whorl or are unknown. Further observations are required for this character.

Fig. 22. Opened flower showing 12 stamens

Filaments.

Filament length varies from 0.5 to 12 mm long, the species can be split into two groups the first with stamens >2.5 mm long or stamens <2.5 mm long. P.quercifolium has the longest filaments at 9--12 mm long, P.microphyllum, P.rivulare, P.rostratum and P.sericeum the shortest at about 0.5 mm long.

Anthers.

A useful anther character is its shape, about half are sagittate, other species are either oblong or ovoid; apex which can be bifid, rounded, or pointed. Sometimes the connective is prolonged as in P.herveyi and P.pseudorostratum.

Another useful anther character is the presence or absence of hairs on the thecae. Species with hairs present are: P.dasyphyllum, P.gutta, P.herveyi, P.leiocarpum, P.microphyllum, P.obtusifolium, P.ridleyi, P.rivulare, P.rostratum and P.stipulare. While for P.psuedocuneatum, P.pseudorostratum, P.quercifolium, P.sericeum and P.walsurifolium hairs were absent. For P.calophyllum, P.cochleariifolium, P.decurrens, P.majas and P.rioense presence or absence of hairs is not yet known.

A potentially useful character is the position of attachment of thecae, variations seen include dorsifixed either near apex, middle, or near base, and basifixed. This requires further study.

Ovary.

The ovary is always superior, syncarpous and with one ovule per locule. Variations are seen in shape, locule number and hairs. Locule number is commonly six although P.sericeum has seven locules and P.quercifolium five to six.

Most species have hairs present on the ovary, although P.ridleyi is sometimes glabrous. Of the 20 Brunei species, 10 have an entirely hairy ovary, five have hairs on the upper ½ with the lower ½ glabrous (P.gutta, P.leiocarpum, P.pseudocuneatum, P.riense, P.rostratum). P.cochleariifolium has hairs at the base but is otherwise glabrous, while P.decurrens has hairs at the apex but is otherwise glabrous. P.sericeum is unusual with hairs on the lower ½ of the ovary and the upper ½ glabrous, while P.herveyi has hairs around the middle of the ovary only.

Fig, 23. Cross-section of 6-locular ovary Fig. 24. Ovary with hairs on upper ½ and glabrous lower ½ Style.

The style varies from 1.5--22 mm long. P.quercifolium has the longest at 15--22 mm long, P.microphyllum and P.ridleyi the shortest at less than 3 mm long. Hairs on the style are a useful character. Nine species were glabrous, seven have hairs at the base only, and four have hairs that extend from the base to ¼ or ½ way along the style (P.calophyllum, P.gutta, P.leiocarpum and P.rostratum).

Fruit.

It is difficult to know the maturity of the fruit on the specimens seen, therefore size was not considered a very useful character at this time. Fruit was not available for all specimens and so comparisons could not be made for potentially useful characters such as presence or absence of hairs.

Fig. 25. P.cochleariifolium fruit (Image by P.Wilkie) Seeds.

Seed shape and scar size vary between species. The scar is rough compared to the shiny seed and can cover ¼ to over ½ seed surface. For this study the usefulness of seed characters was limited as little seed material was available.

Fig. 26. Seed of P.rostratum showing scar covering about ½ seed surface

3.7 Methods used for taxonomic account In the following chapter a taxonomic revision of the genus Palaquium for Brunei is given. This involved viewing herbarium specimens from Edinburgh (E), Brunei (BRUN) and Kew (K) herbaria and images from BRUN, K, Herbarium Bogoriense (BO), Leiden (L), Kepong (KEP), University of Malaya (KLU), Paris (P) Singapore (SING), and Sabah (SAN), Sarawak (SAR). In total around 300 specimens and images were viewed. Protologues and type specimen images were also viewed. Flowers from specimens were boiled and dissected when

20 material was available. Images were taken with a binocular microscope using Leica Application Suite version 4.2.

3.8 Vernacular names

Vernacular names have been included for each species. This information has been gathered from specimen labels and from the previous checklists for Brunei. There are a number of different native tribes in Brunei (such as Iban, and Dusun) and information was lacking regarding which native language these names are common to. Further investigation is required to clarify this.

Chapter Four

4. Revision of Palaquium in Brunei

4.1 Palaquium Blanco. Fl. Filip.:403 (1837). Type species: Palaquium lanceolatum. Neotype: Ramos 19483 (K).

Trees. Branching sympodial. Exudate white, from cut bark, twigs, leaves and fruit. Indumentum typically adpressed, sometimes erect. Stipules usually caducous, sometimes persistent. Leaves spirally arranged, in clusters at tips of twigs or well-spaced along twigs. Leaves simple, petiolate, spathulate to oblanceolate, entire, rarely sinuate, revolute or not. Midrib sunken to slightly raised above, prominently to slightly raised below. Secondary veins 5--30 pairs, eucamptodromous or brochidodromous, arching from midrib at 30--90⁰, tertiary veins transverse to parallel, with or without reticulations. Inflorescences in fasciles, 1--10 flowers, axillary, above leaf scars, rarely terminal. Flowers bisexual, actinomorphic. Calyx 2 whorls of 3 sepals, +/- united, the outer whorl valvate, inner whorl imbricate in bud. Corolla 6-lobes, entire, sympetalous, imbricate; tubular to reflexed to urceolate; tube shorter than lobes. Corolla is white-cream, scented and caducous. Stamens usually 12, sometimes 8 or 20, in one or two whorls. Inserted near to or at base of tube. Obdiplostemonous or several clustered opposite petals. Filaments bent or straight. Anthers ovate to sagittate, two theca, extrorse, dorsifixed near apex, middle or near base, or basifixed, hairy or glabrous. Staminodes absent. Ovary superior, syncarpous, 5--9 locular, one ovule per locule, axile placentation, hairy or glabrous. Nectary sometimes present as disc around base of ovary. Style simple, exserted or included. Fruit a berry. Seed number not known, smooth, with a rough scar that is narrow to broad.

4.2 Key to Palaquium of Brunei

1a. Leaf base cuneate or attenuate or decurrent……………...... 2

1b. Leaf base not cuneate or attenuate or decurrent...... 21

2a. Tertiary veins parallel or parallel-reticulate...... 16

2b. Tertiary veins transverse or transverse-reticulate...... 3

3a. Leaves clustered at tips of twigs...... 4

3b. Leaves well-spaced along twigs...... 11

4a. Dense hairs on lower surface of leaves...... 5

4b. Sparse hairs or glabrous on lower surface of leaves...... 7

5a. Leaves 12--35 cm long; corolla to 20 mm long...... 4.P.decurrens

5b. Leaves ≤15 cm long; corolla <10 mm long………………………………………………6

6a. Secondary veins eucamptodromous, arching from midrib at 40--50˚; petiole 1--2 cm long.………………….………..…………………………………….……...…1.P.calophyllum

6b. Secondary veins brochidodromous, arching from midrib at 60--70˚; petiole 2--5 cm long.……………………………………………………………………….……7.P.leiocarpum

7a. Secondary veins arch from midrib ≥60˚...... 8

7b. Secondary veins arch from midrib ≤50˚...... 10

8a. Twigs 2--3.5 mm diameter; pedicel 3--7 mm long...... 20.P.walsurifolium

8b. Twigs ≥4 mm diameter; pedicel ≥15 mm long...... …………………….9

9a. Outer whorl of calyx lobes glabrous on both surfaces...... 2.P.cochleariifolium

9b. Outer whorl of calyx lobes not glabrous on both surfaces...... 10 P.obtusifolium

10a. Lower surface of leaf with sparse golden hairs; style to 6 mm long; seed with wide scar covering half seed surface……...... 6.P.herveyi

10b. Lower surface of leaf glabrous; style 1.5--2 mm long; seed with narrow scar covering less than half seed surface………………..……………...... 14.P.ridleyi

11a. Leaf apex attenuate or with acuminate tip; stamens 12 or 18…...... ……...... 12

11b. Leaf apex rounded, with no acuminate tip; stamens 20...... 19.P.stipulare

12a. Secondary veins ≤12 pairs………………...……………...……..…………………...….13

12b. Secondary veins ≥12 pairs……………..….……....……………………………………14

13a. Lower surface of leaf with dense adpressed hairs…………………,……1.P.calophyllum

13b. Lower surface of leaf without dense adpressed hairs………………....,..3 P.dasyphyllum

14a. Midrib on lower surface with dense simple long hairs……………...…,……....8.P.majas

14b. Midrib on lower surface with no dense simple long hairs……………………...... ……15

15a. Petiole 1.5--2 cm long; secondary veins arch from midrib at 60--70˚; corolla 5--6 mm long; style to 12 mm long…………………...... ,...15.P.rioense

15b. Petiole 3--7 cm long; secondary veins arch from midrib at 35--50˚; corolla 12--16 mm long; style 15--22 mm long………………………...………...... ,...13.P.quercifolium

16a. Lower surface of leaves densely hairy………………………………….………………17

16b. Lower surface of leaves sparsely hairy or glabrous…………….………………………18

17a. Secondary veins 20--30 pairs; upper surface of leaf dries silvery-grey-blue….,..5.P.gutta

17b. Secondary veins 16--20 pairs; upper surface of leaf dries dark orange- brown…………………………………………………………...……………,...7.P.leiocarpum

18a. Corolla reflexed in anthesis; leaves mostly >4 cm long ...... 19

18b. Corolla not reflexed in anthesis; leaves mostly 3--5 cm long…….……………………………………………………………….,...... 9.P.microphyllum

19a. Style 6--10 mm long; corolla 5--7 mm long; connective prolonged...... ,..12.P.pseudorostratum

19b. Style ≤4 mm long; corolla ≤4 mm long; connective not prolonged...... 20

20a. Twigs 2--3 mm diameter; anthers with bifid apex; ovary ovoid…………………………………………………………,………...11.P.pseudocuneatum

20b. Twigs 3--8 mm diameter; anthers with rounded apex; ovary disc- shaped...... ,..17.P.rostratum

21a. Leaf blade (not veins) lower surface densely hairy...... 22

21b. Leaf blade (not veins) lower surface glabrous or occasional hairs present...... 23

22a. Petiole 15--25 mm long; no persistent pairs of stipules...... …….…8.P.majas

22b. Petiole 3--10 mm long; persistent pairs of stipules...... ……………….18.P.sericeum

23. Leaves not oblong, generally ≤25 cm long; leaf apex not acuminate; style >8 mm long…………………………………...... 24

23. Leaves oblong, 23--46 cm long; leaf apex acuminate; style 3--4 mm long...... ……………………………………...... …...... 16.P.rivulare

24. Petiole 2--4 cm long; pedicel 8--10 mm long; stamens 20…...... 19.P.stipulare

24. Petiole 1--1.5 cm long; pedicel 1.5--2 cm long; stamens (12--)18….…..10.P.obtusifolium

4.3 Species descriptions 1. Palaquium calophyllum (Teijsm. & Binn.) Pierre ex Burck. Ann. Jard. Bot. Buitenzorg 5:28 (1885).

Synonyms: Croixia calophylla (Teijsm. & Binn.) Baehni; Dichopsis calophylla (Teijsm. & Binn.) Benth. & Hook. f.; Isonandra calophylla Teijsm. &. Binn.

Type: Teysmann s.n. (holotype BO, isotype K).

Tree to 18 m tall, 65 cm dbh, buttresses unknown, bark greyish-brown, texture unknown, inner bark pale reddish-brown, sapwood unknown. Twigs 2--7 mm diameter, subterete to angular, slightly sulcate, few to numerous leaf and tubercle scars, older twigs glabrous, adpressed golden hairs towards tips. Stipules caducous, linear, to 8 mm long, golden adpressed hairs. Leaves clustered at tips of twigs or well-spaced along twigs. Petiole 1--2 cm long, angular, adpressed golden hairs to tomentose, adaxial groove. Leaf blade 7--14(--20) X 4--9 cm, chartaceous to coriaceous, obovate to elliptic, young oblanceolate, apex rounded or obtuse with acuminate tip, 2--9 mm long, base cuneate, sometimes oblique, decurrent, glabrous, or occasional sparse hairs at base above, dense adpressed golden hairs below. Midrib sunken, glabrous above, raised, angular, adpressed golden hairs below. Secondary veins 7--12 pairs, eucamptodromous, occasionally brochidodromous, briefly running alongside midrib before arching at 40--50⁰ from midrib, upper surface veins slightly sunken, glabrous, lower surface veins raised with adpressed golden hairs. Tertiary veins transverse. Leaf margin revolute, occasionally not revolute. Inflorescence sometimes axillary, mostly from tubercles above leaf scars, ca. 2--6 flowers. Bracts persistent, many, golden hairs. Pedicel 15--20 mm long, angular to flattened, grooved, adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 2--3 X 2 mm, apex obtusely-acute, outer surface golden adpressed hairs, inner surface glabrous, inner whorl of calyx lobes ovate- triangular, 2 X 1--1.5 mm, apex obtusely-acute, margin not obviously scarious or fimbriate, outer surface adpressed golden hairs, inner surface glabrous. Corolla 6 mm long, lanceolate, obtuse at apex, reflexed in anthesis, line of golden hairs on middle of lobes. Stamens 12, point of insertion unknown, filaments 2.5--4.5 mm long, glabrous, anthers sagittate-ovoid, 1.5-- 2mm long, apex acute or bifid. Ovary globose, 3 X 4 mm, 6-loculed, golden hairs. Style to 8 mm long, golden hairs at base, hairs extending ½ way along style. Fruit globose, 2 X 1.5 cm,

24 golden hairs, small stub of style persistent. Seed sub-globose, 11--14 X 10--12 X 8--10 mm, colour unknown, scar covers ⅓ seed surface.

Unseen characters: corolla, stamens, seed. Described from image of type, protologue, van Royen (1960), and Chai & Yii (2002).

Habitat. Mixed dipterocarp forest, secondary forest, stream banks, on sandy or yellow-clay soils.

Altitude. 0 to 400 m.

Distribution. Borneo (and possibly Sumatra, the Philippines, the Moluccas, New Guinea, in Lam1925, 1927).

Fig. 27. Map of P.calophyllum collection locations across range In Brunei. Belait district: Bukit Sawat; Temburong district: Kuala Belalong; Tutong district: Ulu Tutong.

Vernacular names. Njatu dien, nyatoh babi.

Uses. Latex, firewood, parang sheaths.

Proposed IUCN conservation status.Least concern (LC) (see chapter 5).

Key characters. Leaf apex with acuminate tip 2 to 9 mm long, dense adpressed hairs on lower surface of leaf. Corolla lobes reflexed in anthesis, hairs at base of style extend to ½ way along style.

Morphologically similar species. P.dasyphyllum and P.quercifolium also have obovate- elliptic leaves, eucamptodromous secondary veins and transverse tertiary veins. They can be distinguished from P.calophyllum by: absensce of dense adpressed hairs on lower leaf surface in P.dasyphyllum; longer petiole of 3--7 cm in P.quercifolium.

Specimens seen. (i=image seen)

INDONESIA. Borneo. Kalimantan. De Vogel 1662 (BRUNi); Kessler & Ariffin PK2758 (E!); Wilkie 94326 (E!); Teysmann s.n. (Ki).

MALAYSIA. Borneo. Sarawak: S29590 Illias &Mamit (E!).

BRUNEI. Belait district. Bukit Sawat. Ismail 22235 (BRUNi); Watu Awok 20267 (BRUNi). Temburong district: Kuala Belalong. Ashton 3398 (Ki, KEPi); Ashton L1270 (BRUNi). Tutong district: Tasek Merimbun. Joffree 18378 (BRUNi); Ulu Tutong. Ashton 894 (Ki, KEPi).

2. Palaquium cochleariifolium P. Royen. Blumea 10: 545 (1960).

No synonyms. Sometimes spelt P. cochlearifolium.

Type: Buwalda 7810 (holotype L).

Tree to 30 m tall, 45 cm dbh, buttresses unknown, bark dark brown, shallowly cracked or fissured, inner bark pinkish-red, sapwood unknown. Twigs 4--8 mm diameter, terete, numerous leaf scars, glabrous. Stipules caducous, triangular, 1 X 1 mm, glabrous. Leaves clustered at tips of twigs. Petiole 1.5--5 cm long, adaxial groove, angular below, glabrous. Leaf blade (7--)10--22 X 4--8 cm, coriaceous, obovate to ovate, apex rounded to obtuse, sometimes emarginate, or acuminate tip to 10 mm long, base cuneate, shortly decurrent, both surfaces glabrous. Midrib flat, glabrous above, raised, rounded, glabrous below. Secondary veins 6--10 pairs, eucamptodromous, briefly running alongside midrib before arching at 75-- 85° from midrib, veins slightly raised on both surfaces, glabrous. Tertiary veins transverse to transverse-reticulate. Leaf margin not revolute. Inflorescence axillary or terminal, clustered at tips of twigs, of ca. 5--12 flowers. Bracts unknown. Pedicel 15--35 mm long, angular, thickened near apex, glabrous. Flowers. Calyx outer whorl of calyx lobes ovate, 4--6 X 3--5.5 mm, apex obtusely-acute, glabrous on both surfaces, inner whorl of calyx lobes ovate to rounded, 4--6 X 3--5 mm, apex obtuse or rounded, margin scarious, fimbriate, glabrous, outer surface yellowish hairs, inner surface glabrous. Corolla 5--11 mm long, elliptic, apex rounded, not reflexed in anthesis, glabrous on both surfaces. Stamens 12, whorls unknown, inserted at base, filaments 3--10 mm long, angular, white hairs at apex, anthers oblong, 2--3 mm long, apex mucronate. Ovary conical, size unknown, 6-locular, hairs at base. Style 4--9 mm long, sparse hairs at base, not extending along style. Fruit ellipsoid to sub-globose, 2.5 X 2.5 cm, verrucose, glabrous, persistent style. Seed shape unknown, 1.5 X 1 mm, colour unknown, scar covers ½ seed surface.

Unseen characters: all. Described from image of type, protologue, van Royen (1960), and Chai & Yii (2002).

Habitat. Peat swamp forest.

Altitude. Low.

Distribution. Endemic to Borneo.

Fig. 17. Map of P.cochleariifolium collection locations across range In Brunei. Belait district: Badas; Seria.

Vernacular names. Nyatoh, nyatoh jelutong, nyatoh temiang, paga.

Uses. Timber.

Proposed IUCN conservation status. Endangered (EN). (see chapter 5 ).

Key characters. Leaves glabrous and coriaceous. Inflorescence often terminal, outer whorl of calyx lobes glabrous.

Morphologically similar species. P.walsurifolium also has coriaceous and glabrous leaves, it can be distinguished from P.cochleariifolium by its shorter leaves (to 9.5 cm long) and never has a terminal inflorescene.

Specimens seen. (i=image seen)

INDONESIA. Borneo. Kalimantan. Buwalda 7810 (Li).

MALAYSIA. Borneo. Sarawak. Ashton BRUN3248 (BRUNi).

BRUNEI. Belait district: Badas. Anderson BRUN 5647 (BRUNi); Ashton BRUN978 (BRUNi, Ki, KEPi, Li); Anderson S2854 (BRUNi); Smythies, Wood & Ashton SAN17443 (BRUNi, Ki, KEPi). Sungai Belait. Hassan 48496 (BRUNi, KEPi). Seria. Smythies, Wood & Ashton S5860 (BRUNi, Ki, KEPi).

There are three further collections for Brunei with no collector or location information. Unknown 1006 (BRUNi) and two Unknown s.n. (BRUNi).

3. Palaquium dasyphyllum Pierre ex Dubard. Bull. Soc. Bot. France 56 (16): 8 (1909).

Basionym: Isonandra dasyphylla de Vriese, Natuurw. Tijdschr. Ned.-Indië 21: 307 (1860), nom. illeg.

Homotypic Synonym: Madhuca dasyphylla Baehni, Boissiera 11: 37 (1965). Heterotypic Synonym: Palaquium stenophyllum H.J.Lam, Bull. Jard. Bot. Buitenzorg, III, 7: 97 (1925). Tree to 45 m tall, 30 cm dbh, steep buttresses to 0.9m high, or no buttresses, bark brown, smooth to lenticellate, inner bark whitish to red, sapwood white. Twigs 1.5--3 mm diameter, subterete, slightly sulcate, few leaf scars, adpressed or woolly orange-brown hairs towards tips, glabrescent. Stipules caducous, ovate to narrowly triangular, 5--8 mm long, prominent mid-vein, adpressed brown hairs. Leaves well-spaced along twigs. Petiole 1--2.5 cm long, above flattish, below angular, adaxial groove, dense simple or woolly brown hairs, glabrescent. Leaf blade 10--16(--25) X 5--7 cm, chartaceous, elliptic to obovate to oblong, apex obtuse to rounded, broad acuminate tip 10--20 mm long, base attenuate, shortly decurrent, sometimes oblique, glabrous above, glabrous or occasional sparse golden hairs below. Midrib slightly sunken to flat, glabrous above, raised, golden-brown hairs, glabrescent below. Secondary veins 8--12(--18) pairs, eucamptodromous, briefly running alongside midrib before arching at 40--50° from midrib, upper surface veins slightly raised, glabrous, lower surface veins raised, golden-brown hairs, glabrescent. Tertiary veins transverse to transverse-reticulate. Leaf margin revolute. Inflorescence axillary or above leaf scars, ca. 1-- 6 flowers. Bracts semi-persistent, few, orange-brown hairs. Flowers. Pedicel 10--20 mm long, slightly angular, dense golden hairs. Outer whorl of calyx lobes narrowly ovate- triangular, 3 X 1.5 mm, apex obtuse or acute, outer surface dense orange-brown hairs, inner surface glabrous, inner whorl of calyx lobes narrowly ovate-triangular 3 X 1 mm, apex obtuse or acute, margin scarious, slightly fimbriate, glabrous, outer surface golden adpressed hairs, inner surface glabrous. Corolla to 8 mm long, narrowly ovate, apex toothed, not reflexed in anthesis, sparse golden hairs on both surfaces. Stamens 12, in two whorls, inserted 1.5 mm from base, filaments curved, inner 2.5 mm long, outer 3 mm long, anthers sagittate, 3mm long, apex acuminate to 0.5 mm long, or sometimes bifid, dorsifixed close to base, sparse golden hairs. Ovary ovoid, 1.5 X 1 mm, 6-locular, ridged, dense adpressed golden hairs. Style 5--8 mm long, golden hairs at base, not extending along style. Fruit ellipsoid, 2 X 1.5 cm, green, drying light-brown, sparse brown scales, or glabrous, style persistent to 1 cm long, or broken to stub. Seed narrowly ellipsoid, 1.2 X 0.5 mm, colour unknown, scar covers ½ seed surface.

Unseen: seed. Described from Chai & Yii (2002).

Habitat. Hill mixed dipterocarp forest on sandy or yellow-clay soils.

Altitude. 800 to 1200 m.

Distribution. Borneo (and possibly Riouw, van Royen 1960 cites 1 collection).

Fig. 28. Map of P.dasyphyllum collection locations across range In Brunei. Temburong district: Kuala Belalong.

Vernacular names. Nyatoh, beitis, njato batu.

Uses. Unknown.

Proposed IUCN conservation status. Least concern (LC). (see chapter 5 ).

Key characters. Leaf apex with broad acuminate tip 10--20 mm long, leaves sparsely hairy or glabrous. Inner and outer calyx whorls of equal length.

Morphologically similar species. P. calophyllum and P. quercifolium also have obovate- elliptic leaves, eucamptodromous secondary veins and transverse tertiary veins. They can be distinguished from P.dasyphyllum by: presence of dense adpressed hairs on lower leaf surface in P.calophyllum; longer petiole of 3--7 cm in P.quercifolium.

Based on images P.dasyphyllum and P.rostratum could be confused due to similar leaf shape. From herbarium specimens the two can be distinguished by tertiary veins, which for P.rostratum are parallel-reticulate, and for P.dasyphyllum are transverse-reticulate.

Notes. No previously cited material for Brunei.

Specimens seen. (i=image seen)

INDONESIA. Borneo. Kalimantan. Lee SL410 (E!); Teysmann s.n. (Pi). MALAYSIA. Borneo. Sabah. Wilkie & Jumian SAN152057 (E!); Kulip SAN93647 (E!); Sarawak. Ismawi S29676 (E!). BRUNEI. Temburong district: Bukit Pagon. Ashton 1835 (BRUNi); Kuala Belalong. Ashton 3448 (BRUNi); Ashton 3736 (BRUNi).

4. Palaquium decurrens H.J.Lam. Bull. Jard. Bot. Buitenzorg 111. 7: 51 (1925).

Homotypic synonym: Croixia decurrens (H.J.Lam) Baehni, Boissiera 11:110 (1965).

Type: Hallier 357 (holotype BO).

Tree to 35 m tall, 90 cm dbh, steeply buttressed to 2 m high, 60 cm long, bark pink and grey mottled, shallowly fissured to smooth, inner bark unknown, sapwood unknown. Twigs 7--10 mm diameter, subterete to angular, sulcate, many leaf and tubercle scars, mostly glabrous, adpressed golden hairs towards tips. Stipules caducous, lanceolate, to 6 mm long, golden hairs. Leaves clustered at tips of twigs. Petiole 2.5--3.5 cm long, angular, adaxial groove almost closed, adpressed golden hairs, glabrescent. Leaf blade (6--)12--35 X 5--11 cm, chartaceous to coriaceous, oblanceolate, apex rounded to slight emarginate, occasionally attenuate, base attenuate, decurrent, glabrous above, dense adpressed golden hairs below. Midrib sunken, glabrous above, raised, adpressed golden hairs below. Secondary veins 10--21 pairs, eucamptodromous, briefly running alongside midrib before arching at 50--60⁰ from midrib, upper surface veins flat, glabrous, lower surface veins raised, adpressed golden hairs. Tertiary veins transverse. Leaf margin slightly revolute to not revolute. Inflorescence from tubercles above leaf scars, ca. 3--8 flowers. Bracts persistent, many, golden hairs. Pedicel 10- -20 mm long, angular to flattened, grooved, adpressed golden hairs to glabrous. Flowers. Outer whorl of calyx lobes triangular to ovate-triangular, 5 X 4 mm, apex obtusely-acute, outer surface adpressed golden hairs, inner surface glabrous, inner whorl of calyx lobes triangular to ovate-triangular, 5 X 3 mm, obtusely-acute, margin scarious, fimbriate, glabrous, outer surface adpressed golden hairs, inner surface glabrous. Corolla 6-lobes, to 20 mm long, lobes lanceolate, apex obtuse, not reflexed in anthesis, hairs at base of outer surface, otherwise glabrous. Stamens 12, whorls unknown, point of insertion unknown, filaments 1 mm long, glabrous, anthers ovoid, 3-4 mm long, apex obtusely acuminate. Ovary subglobose, 1.5 X 2 mm, 6-locular, brown hairs at apex, otherwise glabrous. Style 7--8 mm long, glabrous. Fruit globose, 1.5 X 1.5 cm, sometimes with ca. 8 vertical ridges, adpressed golden hairs, glabrescent, stub of style persistent. Seed. subglobose-ellipsoid, 2 X 1.5 cm, colour unknown, scar covers ½ seed surface.

Unseen characters: corolla, stamens, ovary and seed. Described from protologue, van Royen (1960), and Chai & Yii (2002).

Habitat. Mixed dipterocarp forest on sandy soil.

Altitude. 300 to 600 m.

Distribution. Endemic to Borneo.

Fig. 29. Map of P.decurrens collection locations across range In Brunei. Belait district: Ulu Palangaoung.

Vernacular names. Njatu darod, Iban: Sakat.

Uses. Unknown.

Proposed IUCN conservation status. Vulnerable (VU). (see chapter 5 ).

Key characters. Leaf oblanceolate, 12--28 cm long, dense adpressed hairs on lower leaf surface. Long calyx lobes to 5 mm, inner and outer calyx whorls of equal length.

Morphologically similar species. P. majas also has oblanceolate leaves of similar size to P.decurrens. It can be distinguished from P.decurrens by its leaf base which is not decurrent (or very shortly decurrent) and by its simple, erect (non-adpressed) indumentum.

Notes. No previously cited material for Brunei.

Specimens seen. (i=images seen)

INDONESIA. Borneo. Kalimantan. Ridsdale PBU26 (E!); Hellier 357 (BOi).

MALAYSIA. Borneo. Sarawak: Paie & Mamit S28973(E!); Ismawi S40541 (KEPi).

BRUNEI. Belait district: Ulu Palangaoung. Ashton 5635 (BRUNi).

5. Palaquium gutta (Hook) Baill. Traite Bot. Mѐd. Phan. 2 (add): 1500, 1313- 1314 (1884).

Basionym: Isonandra gutta Hook., London J. Bot. 6: 463 (1847).

Homotypic Synonyms: Dichopsis gutta (Hook.) Benth. in G.Bentham & J.D.Hooker, Gen. Pl. 2: 658 (1876); Croixia gutta (Hook.) Baehni, Boissiera 11: 110 (1965).

Heterotypic Synonyms: Isonandra percha Hook., London J. Bot. 6: 610 (1847); Palaquium borneense Burck, Ann. Jard. Bot. Buitenzorg 5: 26 (1885); Palaquium oblongifolium (Burck) Burck, Ann. Jard. Bot. Buitenzorg 5: 25 (1885).

Type: Lobb 290 (K).

Tree to 45 m tall, 120 cm dbh, spreading buttresses to 1 m high, 3 m long, bark brown to greyish-brown, smooth to slightly fissured, inner bark pinkish-red, sapwood brown, exudate copious, from cut trunk, twigs and leaves. Twigs 2--6 mm diameter, subterete to angular, sulcate, few to numerous leaf and tubercle scars, adpressed or tomentose orange-brown or greyish hairs, glabrescent. Stipules caducous, triangular to ovate, 1--2.5 mm long, golden- brown hairs. Leaves loosely clustered at tips of twigs or well-spaced along twigs. Petiole 1--5 cm long, angular, grooved, adpressed or tomentose golden-brown hairs, glabrescent, adaxial groove long, or closed. Leaf blade (4--)8--15 X 3--6.5 cm, chartaceous to coriaceous, elliptic to obovate to oblanceolate, apex acuminate, tip to 7 mm long, or sometimes rounded or emarginate or obtuse, base attenuate, shortly decurrent, golden hairs towards base, midrib and margins when young, becomes glabrous, drying silvery-grey-blue above, dense adpressed golden hairs, occasionally sparse below. Midrib sunken, glabrous or sparse golden hairs above, raised, adpressed golden hairs, glabrescent below. Secondary veins 20--30 pairs, brochidodromous, briefly running alongside midrib before arching at (65--)70--80° from midrib, upper surface veins slightly raised or flat, glabrous, lower surface veins slightly raised to flat, adpressed golden hairs. Tertiary veins parallel to parallel-reticulate or reticulate. Leaf margin slight revolute, golden hairs on margin when young, becomes glabrous. Inflorescence axillary or from tubercles above leaf scars, ca. 4--8 flowers. Bracts unknown. Pedicel 2--10 mm long, angular, adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate- triangular, 3 X 3 mm, apex obtusely-acute, outer surface dark golden-brown hairs, inner surface sparse orange-brown hairs, inner whorl of calyx lobes obtuse to rounded, 3 X 3 mm, apex blunt or toothed, scarious margins, fimbriate, glabrous, inner surface glabrous. Corolla 9 mm long, narrowly ovate, apex obtusely-acute, fimbriate, not reflexed in anthesis, margins fimbriate, glabrous. Stamens 12, whorls unknown, inserted 2.5 mm from base, filaments 2.5 mm long, glabrous, anthers sagittate, 2.5 mm long, apex mucronate or blunt, dorsifixed near base, golden hairs along edges and between thecae. Ovary globose or discoid, 1 X 1.5--2 mm, 6-locular, dense golden hairs all over or on top ½ only. Style 7--8 mm long, ridged, golden hairs at base, extending ¼ way along style. Fruit ellipsoid, 2 X 1.2 cm, rugose, dense adpressed golden-brown hairs, stub of style persistent. Seed ovoid or ellipsoid, 1.2--3 X 1-- 1.7 X 0.6--1 cm, olive-brown to dark-brown, scar unknown.

Unseen: seed. Described from van Royen (1960).

Habitat. Mixed dipterocarp forest and river banks, on sandy, clayey or alluvial soils.

Altitude. 0 to 400 m.

Distribution. Borneo, Sumatra and Peninsular Malaysia.

Fig. 30. Map of P.gutta collection locations across range In Brunei. Temburong district: Kuala Belalong.

Vernacular names. Getah, nyatoh rian, nyatoh durian, rian

Uses. Latex.

Proposed IUCN conservation status. Near Threatened (NT). (see chapter 5 ).

Key characters. Many secondary veins, 20 to 30 pairs, brochidodromous, angle of secondary veins from midrib 70 to 80°, tertiary veins parallel-reticulate. Corolla 9 mm long, tube to 2.5 mm, hairs on style extend along ¼ of its length.

Morphologically similar species. Possible confusion with P.leiocarpum which also has brochidodromous secondary veins and leaves and petioles of similar length as P.gutta. The two can be distinguished by tertiary veins, P.leiocarpum with mostly transverse to transverse- reticulate and occasional parallel veins, whereas P.gutta has mostly parallel to parallel- reticulate tertiary veins.

Notes. No previously cited material for Brunei.

Specimens seen. (i=image seen)

MALAYSIA. Peninsula Malaysia: Curtis 780 (K!); Curtis 3582 (K!); T. & P. 362 (K!); Whitmore FRI12527 (Ki, KEPi); Wilkie FRI72142 (E!); Wilkie FRI52919 (E!). Singapore:

Lobb 290 (E!); Maingay 983 (K!); Sinclair 5474 (E!); Wilkie PW536 (E!); Wilkie & Gwee PW504 (E!).

BRUNEI. Temburong district: Kuala Belalong. Ashton 60 (BRUNi); Ashton 1507 (BRUNi).

6. Palaquium herveyi King & Gamble., J. Asiat. Soc. Bengal. Pt2. Nat. Hist. 74 (2): 197 (1906).

Homotypic synonym: Croixia herveyi (King & Gamble) Baehni, Boissiera 11: 111 (1965).

Type: Hervey s.n. (K).

Tree to 36 m tall, 152 cm dbh, buttresses to 1.8 m high, 120 cm long, bark reddish-brown, smooth, inner bark pale-pink to reddish, sapwood white. Twigs 3--5 mm diameter, subterete to angular, sulcate, few to numerous leaf scars and tubercles, mostly glabrous, short adpressed golden hairs towards tips. Stipules caducous, triangular-ovate, to 4 mm long, golden hairs. Leaves loosely clustered at tips of twigs. Petiole 1--1.5 cm long, flattish with slight ridge above, no adaxial groove, rounded below, sometimes slightly verrucose, adpressed golden hairs, glabrescent. Leaf blade (3--)5--7(--12) X (2--)3--4.5(--6) cm, chartaceous to coriaceous, obovate to elliptic, apex rounded to obtuse to emarginate, base cuneate to attenuate, decurrent, sparse adpressed whitish hairs above, sparse adpressed golden hairs below, lower surface slightly punctate. Midrib raised or flat, golden hairs near base, glabrescent above, raised, sometimes wide and flattened, golden hairs, glabrescent below. Secondary veins 5--10 pairs, eucamptodromous, occasionally brochidodromous, briefly running alongside midrib before arching at 40--50⁰ from midrib, upper surface veins faint, glabrous, lower surface veins slightly raised to flat, sparse golden hairs. Tertiary veins transverse, occasionally transverse-reticulate. Leaf margin not revolute. Inflorescence axillary or from tubercles above leaf scars, ca. 2--6 flowers. Bracts persistent, many, golden hairs. Pedicel 2--6 mm long, angular to flattened, grooved, adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 2 X 3 mm, apex obtusely-acute, outer surface adpressed golden hairs, inner surface glabrous, inner whorl of calyx lobes obtuse to rounded, 2 X 2 mm, apex rounded, margin scarious, fimbriate, glabrous, outer surface adpressed golden hairs from middle to tip, inner surface glabrous. Corolla 4 mm long, narrowly urceolate, apex rounded, not reflexed in anthesis, golden hairs at base on both surfaces, otherwise glabrous. Stamens 12, in two whorls, outer whorl inserted 1 mm from base, inner whorl inserted 0.5 mm from base, filaments 1 mm long, glabrous, anthers sagittate, 1--1.2 mm long, apex pointed tip of prolonged connective, sparse golden hairs. Ovary subglobose, 1 X 1 mm, 6-locular, ridged, short golden hairs around middle. Style 6 mm long, ridged, glabrous. Fruit ellipsoid, 2 X 1.3 mm, slightly verrucose, glabrous, small stub of style persistent. Seed narrowly ellipsoid, 7 X 2.5 mm, blackish, scar covers ½ seed surface.

Unseen: seed. Described from van Royen (1960).

Habitat. Lowland and hill mixed dipterocarp forest, on sandy or clayey soils.

Altitude. 100 to 1200 m.

Distribution. Borneo. and Peninsular Malaysia.

Fig. 31. Map of P.herveyi collection locations across range In Brunei. Temburong district: Kuala Temburong Machang

Vernacular names. Jongek, nyatoh putih, nyatoh batu, nyatoh nanglia.

Uses. Unknown.

Proposed IUCN conservation status. Endangered (EN). (see chapter 5 ).

Key characters. Leaves 5--7 cm long, obovate to elliptic, sparse adpressed hairs on lower leaf surfacehairs. Seed sacr covers ½ seed surface.

Morphologically similar species.Confusion occurs between P.herveyi and P. walsurifolium. Molecular phylogenetic work confirms they are separate species (Wilkie, unpubl.). P.walsurifolium can be distinguished by its glabrous leaves, greater secondary vein angle of 60--70⁰ and longer corolla at 6--7mm long.

Specimens seen. (i=image seen)

MALAYSIA. Peninsular Malaysia. Ando et al. 417 (K!); Bahar 25231 (KEPi); Ibrahim KEP42821 (KEPi); King & Gamble s.n. (K!); Ng FRI1254 (SINGi); Wilkie et al. FRI75010 (E!); Zainuddin KEP75873 (KEPi). Borneo. Sabah. Aban SAN61787 (SANi); Aban SAN60686 (SANi); Aban SAN56420 (SANi). Sarawak. Illias S27784 (E!).

BRUNEI. Temburong district: Kuala Temburong Machang. Ashton BRUN2607 (BRUNi, Ki, KEPi).

7. Palaquium leiocarpum Boerl., Bull. Inst. Bot. Buitenzorg 5: 24 (1900).

Homotypic synonym: Croixia leiocarpa (Boerl.) Baehni, Boissiera 11: 111 (1965).

Heterotypic synonym: Palaquium molle Pierre ex Becc., For. Borneo: 559 (1902).

Lectotype: Romburgh 2 (lectotype BO).

Tree to 30 m tall, 35 cm dbh, stilt roots or not, bark dark reddish-brown, fissured, inner bark light-brown, sapwood pale yellow, exudate fast to appear. Twigs 3--7 mm diameter, subterete to angular, sulcate, numerous leaf and tubercle scars, verrucose/enlarged lenticels frequent, mostly glabrous, sparse greyish-orange-brown tomentose towards tips. Stipules caducous, ovate-triangular to 5 mm long, greyish-brown hairs. Leaves loosely clustered at tips of twigs. Petiole 2--5 cm long, angular, adaxial groove closed to almost-closed, greyish-brown tomentose, glabrescent. Leaf blade 9--15 X 5--7 cm, coriaceous, oblong to obovate, apex rounded, shortly obtuse or acuminate, tip to 3 mm long, base cuneate, sometimes oblique, shortly decurrent, glabrous, drying dark orange-brown above, dense adpressed golden-brown hairs below. Midrib sunken, glabrous above, raised, dense adpressed golden-brown hairs below. Secondary veins 16-20 pairs, brochidodromous, occasionally eucamptodromous, briefly running alongside midrib before arching at 60--70⁰ from midrib, upper surface veins slightly raised, faint, glabrous, lower surface veins slightly raised, adpressed golden-brown hairs. Tertiary veins mixture of transverse, transverse-reticulate, reticulate, parallel or parallel reticulate, sometimes on same leaf. Leaf margin occasionally sinuate, slight revolute. Inflorescence axillary or from tubercle above leaf scars, ca. 3--5 flowers. Bracts persistent, many, orange-brown hairs. Pedicel 7--10 mm long, angular to flattened, grooved or not, adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes 3--5 X 3--4.5 mm, ovate- triangular, apex acute or blunt, outer surface adpressed dark orange-brown hairs, inner surface sparse golden hairs or glabrous, inner whorl of calyx lobes 2.5--5 X 2--4 mm, ovate- triangular, apex obtusely-acute, margin scarious, fimbriate, glabrous, outer surface adpressed golden hairs, inner surface sparse golden hairs or glabrous. Corolla 6-lobes, 5--7 mm long, narrowly ovate, apex obtuse, fimbriate, not reflexed in anthesis, outer surface glabrous, inner surface occasional golden hairs. Stamens 9--12, whorls unknown, inserted 1--1.5 mm from base, filaments 1.5--2 mm long, glabrous, anthers sagittate, 2--3 mm long, apex long pointed tip, dorsifixed near base, sparse golden hairs. Ovary globose or conical, 1 X 1--2 mm, 6- locular, dense golden hairs, or glabrous on lower ½ and golden hairs on upper ½. Style to 10 mm long, glabrous or with golden hairs at base extending ¼ way along style. Fruit globose, 2 X 2 cm, glabrous, stub of style persistent. Seed shape ellipsoid or subglobose, 6--18 X 1--15 mm, colour unknown, scar covers ½ seed surface.

Unseen: seed. Described from van Royen (1960).

Habitat. Swamp forest, mixed dipterocarp forest, kerangas forest.

Altitude. 0 to 1500 m.

Distribution. Borneo and Penninsular Malaysia. (and possibly Sulawesi and Sumatra, mentioned in van Royen, 1960, and Chai & Yii, 2002)

Fig. 32. Map of P.leiocarpum collection locations across range In Brunei. Belait district: Sungai Ingei. Temburong district: near Pagon ridge

Vernacular names. Nyatoh, nyatoh temiang.

Uses. Timber, latex.

Proposed IUCN conservation status. Least concern (LC). (see chapter 5 ).

Key characters. Leaves oblong to obovate, coriaceous, glabrous, secondary veins brochidodromous, tertiary veins variable on same leaf. Stamens 9--12

Morphologically similar species. Confusion is possible with P.gutta which also has brochidodromous secondary veins and leaves and petioles of similar length as P.leiocarpum. The two can be distinguished by tertiary veins, P.gutta has mostly parallel to parallel- reticulate tertiary veins, P.leiocarpum has mostly transverse to transverse-reticulate and occasional parallel veins.

Notes. The lectotypified specimen in BO is not very similar to the type specimen, yet is matches the protologue and appears to be a better match than the type specimen of the synonym P.molle.

Specimens seen. (i=images seen)

INDONESIA. Borneo. Kalimantan. Kessler PK1569 (E!); Romburgh 2 (BOi); Sidiyasa 2531 (E!).

MALAYSIA. Borneo. Sabah: Soepadmo FRI41305 (E!).

BRUNEI. Belait district: Sungai Ingei. Ashton BRUN149 (Ki). Temburong district: near Pagon ridge. Wong 1910 (BRUNi, Ki).

8. Palaquium majas H.J.Lam, Bull. Jard. Bot. Buitenzorg, III, 7: 66 (1925).

Homotypic synonym: Croixia majas (H.J. Lam) Baehni, Boissiera 11: 110 (1965).

Type: Jaheri 1085 (holotype BO, isotype L).

Tree to 12 m tall, 25 cm dbh, buttresses unknown, bark dark-brown, fissured, inner bark pink, sapwood unknown. Twigs 3--6 mm diameter, subterete to angular, sulcate, few leaf scars, dense erect orange-brown hairs (not adpressed), occasional glabrescent patches. Stipules caducous, ovate, to 5 mm long, orange-brown hairs. Leaves well-spaced along twigs. Petiole 1.5--2.5 cm long, angular, slight adaxial ridge, no adaxial groove, dense erect orange-brown hairs, occasional glabrescent patches. Leaf blade 16--22 X 8--11.5 cm, chartaceous to coriaceous, obovate to oblanceolate, apex obtusely-acuminate, tip to 6 mm long, base obtusely-attenuate, frequently oblique, not decurrent or very shortly decurrent, glabrous above, dense, long, erect orange-brown hairs below. Midrib sunken, light-brown tomentose, glabrescent above, raised, dense, long, erect orange-brown hairs below. Secondary veins 14-- 18 pairs, brochidodromous, briefly running alongside midrib before arching at 50--60° from midrib, upper surface veins sunken, glabrous, lower surface veins raised, long erect orange- brown hairs. Tertiary veins transverse-reticulate. Leaf margin sometimes sinuate, not revolute, dense orange-brown hairs at margin. Inflorescence axillary, ca. 5--9 flowers. Bracts caducous, orange-brown hairs. Pedicel 10--20 mm long, grooved, dense simple or tomentose orange-brown hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 4 X 3 mm, apex obtusely-acute, outer surface dense orange to light-brown hairs, inner surface glabrous, inner whorl of calyx lobes oblong-ovate, 4.5 X 2 mm, apex blunt, margin scarious, fimbriate, glabrous, outer surface light-brown hairs down middle of lobe, inner surface glabrous. Corolla 7--10 mm long, elliptic-oblong, apex acute, not reflexed in anthesis, glabrous on both surfaces. Stamens 18, whorls unknown, filaments 1.5--2 mm, point of insertion unknown, glabrous, anthers oblong, 3--3.5 mm long, apex bifid. Ovary ovoid, 1.5 X 2 mm, 6-locular, golden-brown hairs. Style 10--11 mm long, hairs at base then glabrous. Fruit globose, 1.8 X 1.5 cm, pale yellow-green, drying dark-brown, sparse orange-brown hairs, glabrescent, style persistent on to 7 mm long, or broken to stub. Seed ellipsoid, 9--18 X 6--13 X 5--11 mm, colour unknown, scar covers ½ seed surface.

Unseen: corolla, stamens, ovary, style, seed. Described from type, protologue, van Royen (1960), and Chai & Yii (2002).

Habitat. Mixed dipterocarp forest on sandy or clayey soils.

Altitude. 0 to 700 m

Distribution. Endemic to Borneo.

Fig. 33. Map of P.majas collection locations across range In Brunei. Belait district: Bukit Teraja. Brunei-Muara district: Sungai Brunei.

Vernacular names. Nyatoh.

Uses. Unknown.

Proposed IUCN conservation status. Endangered (EN). (see chapter 5 ).

Key characters. Long, simple, non-adpressed orange-brown hairs on twig, petiole, under surface of leaves and pedicel, apex obtusely-acuminate, densely hairy leaf margins. Stamens 18.

Morphologically similar species. P.decurrens and P.stipulare both similar with regard to leaf size and shape, but neither has the erect, non-adpressed indumentum seen in P.majas.

Notes. Not previously recorded in Brunei.

Specimens seen: (i=image seen)

INDONESIA. Borneo. Kalimantan. Church, Mahyar & Afriastini 2091 (E!); Church, Mahyar & Afriastini 2005 (E!).

MALAYSIA. Borneo. Sarawak. Illias & Munting S48673 (KEPi, SANi);

BRUNEI. Belait district: Bukit Teraja. Coode & Kirkup 6910 (KEPi). Brunei-Muara district: Sungai Brunei. Jaheri 1085 (Li).

9. Palaquium microphyllum King & Gamble., J. Asiat. Soc. Bengal. Pt2. Nat. Hist. 74 (2): 196 (1906).

Homotypic synonym: Croixia microphylla (King & Gamble) Baehni, Boissiera 11: 110 (1965).

Type: Ridleyi 10840 (holotype SING).

Tree to 40 m tall, 180 cm dbh, rounded or narrow buttresses to 4 m high, bark brown to grey- brown, smooth or shallowly fissured, flaking in places, inner bark pinkish to dark red, sapwood pinkish-cream, exudate fast to appear. Twigs 2--4 mm diameter, terete, angular towards tips, sulcate, few to numerous leaf and tubercle scars, verrucose, reddish-brown or golden hairs towards tips, older twigs glabrous. Stipules not seen, either absent or caducous. Leaves loosely clustered at tips of twigs. Petiole 0.5--1.5 cm long, flattish, with ridge or slight adaxial groove above, angular below, glabrous or orange-brown-greyish hairs, glabrescent. Leaf blade (1--)3--5(--8) X 1.5--3 cm, chartaceous to coriaceous, spathulate to obovate to elliptic, apex obtuse or shortly attenuate with tip to 3 mm long, occasionally rounded, base cuneate, decurrent, glabrous or sparse golden hairs on both surfaces, sometimes punctate below. Midrib slightly raised to flat to sunken, glabrous or hairs near base above, raised, orange-brown hairs, glabrescent below. Secondary veins ca. 10--20 pairs, brochidodromous, do not appear to run alongside midrib, arch at 60--70⁰ from midrib, upper surface veins faint, glabrous, lower surface veins faint, glabrous. Tertiary veins parallel- reticulate to reticulate, faint. Leaf margin revolute or not. Inflorescence mostly above leaf scars, sometimes axillary, sparse along stem or densely whorled around stem. Bracts persistent, orange-brown hairs. Pedicel 3--4 mm long, angular to flattened, grooved, adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 3 X 3 mm, apex obtusely-acute, outer surface golden hairs, inner surface sparse golden hairs, inner whorl of calyx lobes ovate-triangular, 2.5 X 2 mm, apex obtusely-acute, margin scarious, fimbriate, glabrous, outer surface golden hairs, inner surface glabrous. Corolla 2.5--3 mm long, urceolate, apex blunt, not reflexed in anthesis, outer surface long golden hairs from base to middle, inner surface glabrous or sparse golden hairs between filaments. Stamens 12, in two whorls, inserted 0.5 mm from base, inner filaments 0.5 mm long, outer filaments 0.8 mm long, anthers sagittate, 1--1.5 mm long, apex pointed, blunt or bifid, dorsifixed near base, sparse golden hairs. Ovary conical, 1 X 1 mm, 6-locular, dense golden hairs. Style 2--3 mm long, golden hairs at base, then glabrous. Fruit globose to ellipsoid, 2 X 1.5 cm, sparse orange-brown hairs, glabrescent, style persistent. Seed ovoid-ellipsoid, 2 X 1.2 cm, glossy, pale yellow-brown, scar covers ½ seed surface.

Unseen: seed. Described from van Royen (1960).

Habitat. Mixed dipterocarp forest, swamp forest.

Altitude.100 to 500 m.

Distribution. Borneo and Peninsular Malaysia (and possibly Sumatra and Riouw, in van Royen, 1960).

Fig. 34. Map of P.microphyllum collection locations across range In Brunei. Belait district: Seria.

Vernacular names. Nyatoh merah.

Uses. Timber.

Proposed IUCN conservation status. Near threatened (NT). (see chapter 5 ).

Key characters. Small leaves, 3--5 cm long, spathulate to obovate, secondary veins faint on both surfaces; brochidodromous, tertiary veins parallel-reticulate, also faint.

Morphologically similar species. The consistently small leaves of P.microphyllum are distinctive. P.pseudocuneatum sometimes has small leaves and parallel secondary veins but differ from P.microphyllum as they are eucamptodromous. P.pseudocuneatum has corolla lobes that are reflexed in anthesis unlike P.microphyllum.

Specimens seen.

MALAYSIA. Peninsular Malaysia. Corner 34671 (K!); Everett FRI 14323 (K!); HnR 100140 (K!); Mohd. 66656 (K!); Ogata KEP 110385 (K!); Pennington 11241 (K!); Sinclair 5154 (E!); Ridleyi 10840 (SINGi).

BRUNEI. Belait district: Seria. Smythies, Wood & Ashton S5886 (BRUNi; Li).

10. Palaquium obtusifolium Burck., Ann. Jard. Bot. Buitenzorg 5: 33 (1885).

Homotypic Synonym: Madhuca obtusifolia (Burck) Baehni, Boissiera 11: 36 (1965).

Heterotypic Synonyms: Palaquium negrosense Merr., Philipp. J. Sci., C 10: 63 (1915);

Palaquium ternatense H.J.Lam, Bull. Jard. Bot. Buitenzorg, III, 7: 103 (1925).

Type: Teysmann s.n. (BO).

Tree to 45 m tall, dbh unknown, buttresses unknown, bark unknown, sapwood unknown. Twigs 4-7 mm diameter, subterete to angular, sulcate, numerous leaf and tubercle scars, horizontal fissures, mostly glabrous, orange-greyish-brown tomentose towards tips. Stipules caducous, narrowly-triangular to ovate, to 4 mm long, outer surface tomentose, inner glabrous. Leaves loosely clustered at tips of twigs. Petiole 1--1.5 cm long, flattish above, rounded or flattened below, sparse brownish-grey woolly hairs glabrescent, no adaxial groove. Leaf blade (9--)12--18 X 4.5--8 cm, chartaceous, obovate, apex rounded to obtuse to sub-emarginate, base narrowly cuneate to sub-truncate, slight decurrent, glabrous on both surfaces. Midrib flat to slightly sunken, glabrous above, raised, rounded near base becomes flatter towards tip, glabrous below. Secondary veins 10--11 pairs, eucamptodromous, occasional brochidodromous, briefly running alongside midrib before arching at 60--70° from midrib, upper surface veins slightly raised, glabrous, lower surface veins raised, glabrous. Tertiary veins transverse to transverse-reticulate. Leaf margin sometimes sinuate, not revolute. Inflorescence axillary or from tubercles above leaf scars, ca. 1--6 flowers. Bracts not seen. Pedicel 15--20 mm long, angular, grooved, orange-brown to greyish tomentose, glabrescent. Flowers. Calyx outer whorl of calyx lobes, broadly ovate, 3--3.5 X 2.5--3.5 mm, apex acute, outer surface adpressed hairs, inner surface glabrous, inner whorl of calyx lobes rounded, size 2.5 X 2.5 mm, apex rounded, margin scarious, fimbriate, glabrous. Corolla 6--8 mm long, ovate-oblong, apex blunt, reflexed in anthesis, outer surface hairs at mid-line, otherwise glabrous. Stamens (12--)18, whorls unknown, 4--5.5 mm long, insertion point unknown, filaments 2.5--3.5 mm long, glabrous, anthers oblong-ovoid, 2.5--3.5 mm long, apex mucronate or bifid, sparse golden hairs. Ovary conoid, 1.5 X 2.5 mm, 6-locular, yellow tomentose. Style 10--15 mm long, glabrous. Fruit ellipsoid, 3.5 X 1.5 cm, style persistent to 1 cm long. Seed shape ovoid, 2.5--3.5 X 1.6--2.2 cm, pale greyish-brown, scar covers ¼ seed surface.

Unseen: flower and seed. Described from van Royen (1960).

Habitat. Mixed dipterocarp forest on sandy or clayey soils.

Altitude. 0 to 100 m.

Distribution. Borneo and Sulawesi (and possibly Sumatra, Bali, the Phillipines and New Guinea, in van Royen, 1960).

Fig. 35. Map of P.obtusifolium collection locations across range In Brunei. Tutong district: Andalau Forest Reserve

Vernacular names. Nyatoh.

Uses. Unknown.

Proposed IUCN conservation status. Endangered (EN). (see chapter 5 ).

Key characters. Leaves glabrous, leaf base narrowly cuneate to truncate, slight decurrent. Stamens (12--)18.

Morphologically similar species. P.stipulare also has obovate leaves with rounded to sub- emarginate apex, and cuneate to sub-truncate base. It can be distinguished from P.obtusifolium by its longer petiole (2--4 cm long) and greater number of secondary veins with 10--19 pairs.

Specimens seen. (i=image seen)

SULAWESI. Teysmann s.n. (K!).

BRUNEI. Tutong district: Andalau Forest Reserve. Smythies SAN17492 (Ki).

11. Palaquium pseudocuneatum H.J.Lam. Bull. Jard. Bot. Buitenzorg 111. 8: 391 (1927).

Heterotypic synonym: Croixia pseudocuneata (H.J.Lam) Baehni, Boissiera 11: 110 (1965).

Type: Egon 340 (non 306) (BO).

Tree to 34 m tall, dbh unknown, buttresses unknown, bark unknown, inner bark unknown, sapwood unknown. Twigs 2--3 mm diameter, terete or angular, mostly glabrous, sparse adpressed hairs at tips. Stipules caducous, shape unknown, <1 mm long, indumentum unknown. Leaves clustered at tips of twigs or well-spaced along twigs. Petiole 0.7--1 cm long, angular, adaxial groove, glabrous. Leaf blade 4--11 X 1.5--4.5 cm, sub-coriaceous, spathulate to obovate, apex rounded to obtuse, sometimes shortly acuminate, base cuneate, decurrent, both surfaces glabrous. Midrib sunken, glabrous above, raised, angular, glabrous below. Secondary veins 10--12 pairs, eucamptodromous, unknown whether they briefly run alongside midrib, angle of veins from midrib 60--80˚. Upper and lower surface veins slightly raised, glabrous. Tertiary veins parallel-reticulate. Leaf margin not revolute. Inflorescence axillary or from leaf scars, ca. 2--4 flowers. Pedicel 5--12 mm long, angular, orange-brown tomentose. Flowers. Calyx outer whorl of calyx lobes ovate, 3--4 X 2--3 mm, apex obtusely- acute, outer surface adpressed golden hairs, inner surface sparse hairs, inner whorl of calyx lobes, ovate-triangular, 3 X 2 mm, apex obtusely- acute, outer surface adpressed golden hairs, inner surface sparse hairs. Corolla 3--4 mm long, shape unknown, apex unknown, reflexed in anthesis, golden hairs on outer surface, hairs between filaments. Stamens 12, or sometimes 8, in two whorls, inserted at different levels, point of insertion unknown, filaments 1.5--2.5 mm long, sparse hairs, anthers ovoid, 1--1.5 mm long, apex bifid, connective not prolonged, glabrous. Ovary ovoid, 1.5 X 1.5 mm, 6-locular, golden hairs. Style 2--4 mm long, 6-ridged, hairs at base then glabrous. Fruit globose to ellipsoid, 1.5 X 1.9 cm, glabrous, style persistent. Seed obovoid, 12 X 6 X 5 mm, colour unknown, scar covers ½ seed surface.

Unseen: all. Described from protologue, van Royen (1960), and Chai & Yii (2002).

Habitat. Swamp forest and mixed dipterocarp forest.

Altitude. Low.

Distribution. Endemic to Borneo.

Fig. 36. Map of P.pseudocuneatum collection locations across range

In Brunei: Belait district: Bukit Puan, Seria.

Vernacular names. Nyatoh babi.

Uses. Timber.

Proposed IUCN conservation status. Endangered (EN). (see chapter 5 ).

Key characters. Glabrous leaves with parallel-reticulate tertiary veins. Corolla lobes reflexed in anthesis.

Morphologically similar species. P.pseudorostratum is very similar vegetatively. It can be distinguished from P.pseudocuneatum by floral characters such as its longer style (6--10mm long) which is entirely glabrous.

Specimens seen. (i=image seen)

INDONESIA. Borneo. Kalimantan.

MALAYSIA. Borneo. Sarawak. Anderson KLU2685 (KLUi); Egon A937 (KEPi); Tahir 9246 (BRUNi, KEPi); Tahir 9256 (BRUNi, KEPi).

BRUNEI. Belait district: Bukit Puan. Ashton J759 (BRUNi). Seria. Van Niel 3814 (Li).

12. Palaquium pseudorostratum H.J.Lam. Bull. Jard. Bot. Buitenzorg 111. 8: 393 (1927).

Homotypic synonym: Croixia pseudorostrata (H.J.Lam) Baehni, Boissiera 11: 108 (1965).

Type: NIFS bb 9449 (holotype BO, isotype L).

Tree to 45 m tall, dbh unknown, buttresses unknown, bark reddish-brown, smooth or shallowly fissured, inner bark pinkish-brown, sapwood unknown. Twigs 3--7 mm diameter, subterete to angular, glabrous. Stipules caducous, size, shape and indumentum unknown. Leaves well-spaced along twigs. Petiole 0.5--4 cm long, orange-brown tomentose, glabrescent, flat or ridged or grooved above, angular below. Leaf blade (3--)6.5--14 X 1.7--4 cm, chartaceous-coriaceous, spathulate to obovate, apex rounded or obtuse, rarely with obtusely-acuminate tip, base narrowly cuneate, decurrent, both surfaces glabrous. Midrib sunken, glabrous above, raised, angular, glabrous below. Secondary veins 12--20 pairs, eucamptodromous, unknown whether veins briefly run alongside midrib, angle of veins from midrib 70--85⁰, veins slightly raised, glabrous on both surfaces. Tertiary veins parallel. Leaf margin unknown. Inflorescence axillary or above leaf scars, ca. 4--6 flowers. Bracts unknown. Pedicel 3--4.5(--7) mm long, angular, adpressed orange-brown hairs. Flowers. Calyx outer whorl of calyx lobes ovate, 2--5 X 2--3.5 mm, apex obtuse or acute, outer surface orange-brown hairs, inner surface glabrous, inner whorl of calyx lobes size, shape and indumentum unknown, margins scarious, fimbriate, glabrous. Corolla 5--7 mm long, elliptic- oblong, apex obtuse to rounded, reflexed in anthesis, golden hairs between stamens otherwise

45 glabrous. Stamens 12, in two whorls, point of insertion unknown, stamens opposite petals slightly longer than alternipetalous stamens, filaments 2--4 mm long, golden hairs at base, anthers ovoid, 1.5--2.5 mm long, apex rounded with prolonged connective, glabrous. Ovary ovoid, 1.5 X 1.5 mm, 6-locular, golden-brown hairs on upper 1/2, lower 1/2 glabrous. Style 6- -10 mm long, grooved, glabrous. Fruit globose or ellipsoid, 1.4 X 1.6 cm, glabrous, persistent stub of style. Seed ellipsoid, 11 X 6 X 5 mm, colour unknown, scar covers ½ seed surface.

Unseen characters: all. Described from protologue, image of type, van Royen (1960); Chai & Yii (2002).

Habitat. Peat swamp forest, freshwater swamp forest, kerangas forest.

Altitude. Low.

Distribution. Borneo (and possibly the Philippines, in van Royen, 1960).

Fig. 37. Map of P.pseudorostratum collection locations across range In Brunei: Temburong district: Bukit Biang.

Vernacular names. Nyatoh, nyatoh babi, nyatoh tembaga.

Uses. Unknown.

Proposed IUCN conservation status. Near threatened (NT). (see chapter 5 ).

Key characters. Leaves spathulate to obovate, glabrous, with parallel-reticulate tertiary veins. Corolla lobes reflexed in anthesis.

Morphologically similar species. P.pseudocuneatum is very similar vegetatively. It can be distinguished from P.pseudorostratum by floral characters such as a shorter style (2--4 mm long) with hairs at the base.

Specimens seen. (i=image seen)

INDONESIA. Borneo. Kalimantan. NIFS bb 9449 (BOi).

MALAYSIA. Borneo. Sarawak. Anderson 53 (KEPi); Anderson 60 (KEPi); Anderson 13268 (SANi). Sabah. Madani SAN51680 (SANi); Singh SAN24320 (KEPi, SANi).

BRUNEI. Temburong district: Bukit Biang. Ashton J4486 (BRUNi).

13. Palaquium quercifolium (de Vriese) Burck. Ann. Jard. Bot. Buitenzorg 5: 41 (1885).

Basionym: Isonandra quercifolia de Vriese, Natuurw. Tijdschr. Ned.-Indië 21: 311 (1860).

Homotypic Synonym: Croixia quercifolia (de Vriese) Baehni, Boissiera 11: 108 (1965).

Heterotypic Synonyms: Isonandra macrophylla de Vriese, Natuurw. Tijdschr. Ned.-Indië 21: 309 (1860); Palaquium macrophyllum (de Vriese) Pierre ex Dubard, Bull. Soc. Bot. France 56(16): 9 (1909).

Type: Motley VII 1367 (holotype L).

Tree to 40 m tall, dbh unknown, buttresses unknown, bark reddish-brown, texture unknown, inner bark pale-reddish, sapwood unknown. Twigs 3--10 mm diameter, terete, few to numerous leaf scars, orange-brown tomentose, glabrescent. Stipules caducous, linear, to 10 mm long, outer surface adpressed brown hairs, inner glabrous. Leaves well-spaced along twigs. Petiole 3--7 cm long, adaxial groove, orange-brown tomentose to glabrous. Leaf blade 8--16--32 X 4--10 cm, chartaceous-coriaceous, obovate to oblong or elliptic, apex acuminate, rarely rounded, base cuneate, decurrent, glabrous above, grey-brownish tomentose below. Midrib sunken, glabrous above, raised, rounded, sparse tomentose, glabrescent below. Secondary veins 12--17 pairs, eucamptodromous, occasionally brochidodromous, briefly running alongside midrib before arching at 35--50⁰ from midrib, upper surface veins sunken above, glabrous, raised below, sparse hairs, glabrescent. Tertiary veins transverse. Leaf margin not revolute. Inflorescences axillary, ca. 4--8 flowers. Pedicel 8--14 mm long, orange-brown tomentose. Flowers. Calyx outer whorl of calyx lobes ovate-lanceolate, 4--6 X 2--3 mm, apex obtuse, outer surface dense orange-brown hairs, inner surface sparse hairs, inner whorl of calyx lobes ovate-lanceolate, size unknown, apex obtuse, outer surface dense orange-brown hairs, inner surface sparse hairs. Corolla 12--16 mm long, ovate-lanceolate, apex acute or obtuse, not reflexed in anthesis, fimbriate, orange-brown tomentose on tube. Stamens 12, in two whorls, filaments 9--12 mm long, point of insertion unknown, glabrous, anthers ovoid or sagittate, 2.5--3.5 mm long, apex acuminate, glabrous. Ovary discoid, 0.7-- 1.5 X 1--1.5 mm, 5--6 locular, brown tomentose. Style 15--22 mm long, glabrous. Fruit globose, 2 X 2 cm, glabrous, style persistent. Seed ellipsoid, 1.4 X 1.2 cm, colour unknown, scar unknown.

Unseen characters: all. Described from protologue, image of type, van Royen (1960); Chai & Yii (2002).

Habitat. Lowland mixed dipterocarp forest, freshwater swamp forest, on clayey or alluvial soils.

Altitude. Low.

Distribution. Borneo, Sumatra and Sulawesi.

Fig. 28. Map of P.quercifolium collection locations across range In Brunei. Temburong district: Bukit Tudal.

Vernacular names. Nyatoh, nyatoh babi, nyatoh tembaga.

Uses. Unknown.

Proposed IUCN conservation status. Vulnerable (VU). (see chapter 5 ).

Key characters.

Corolla to 16 mm long, filaments to 12 mm long, style to 22 mm.

Morphologically similar species. P.calophyllum and P.dasyphyllum also have obovate- elliptic leaves, eucamptodromous secondary veins and transverse tertiary veins. They can be distinguished from P.quercifolium by: absensce of dense adpressed hairs on lower leaf surface in P.dasyphyllum; shorter petiole of 2--4 cm in P.calophyllum.

Notes. Some variation from type specimen in protologue and literature. For example leaf length at lowest end of range is 8 cm for type specimen, 17 cm in protologue and 12 cm in van Royen (1960). It would be useful to see material of this species to decide whether this is natural variation within the species, or if they are refering to different species. The name of this species can also cause confusion as in my opinion it is not quercus-like.

Specimens seen. (i=images seen)

INDONESIA. Borneo. Kalimantan. Motley VII 1367 (Li).

BRUNEI: Temburong district.Bukit Tudal. Kirkup & Bygrave 793 (BRUNi).

14. Palaquium ridleyi King & Gamble. J. Asiat. Soc. Bengal. Pt2. Nat. Hist. 74 (2): 196 (1906).

Heterotypic Synonyms: Palaquium ledermannii K.Krause, Bot. Jahrb. Syst. 58: 471 (1923); Palaquium poilanei Lecomte, Fl. Indo-Chine 3: 900 (1930).

Type: Ridleyi 3591a (holotype K; isotypes L, SING).

Tree to 30 m tall, 80 cm dbh, fluted or buttresses to 1 m high, 50 cm long, bark, dark reddish- brown, fissured, inner bark reddish-brown, sapwood light-brown. Twigs 2--4 mm diameter, sub-terete, angular towards tips, sulcate, few small leaf scars, sometimes verrucose, mostly glabrous, adpressed golden-brown hairs towards tips. Stipules caducous, ovate-lanceolate, 2 X 1 mm, brown hairs on outer surface, inner glabrous. Leaves loosely clustered at tips of twigs. Petiole 0.8--1.5 cm long, wide, flat above, no adaxial groove, rounded to angular below, mostly glabrous, occasional short dark hairs. Leaf blade 4.5--6(--14) X 2--3(--5.5) cm, chartaceous, elliptic to obovate, apex rounded to obtuse to short accuminate, base attenuate, decurrent, glabrous on both surfaces, sometimes punctate below. Midrib flat, wide, glabrous above, slightly raised, grooved, glabrous below. Secondary veins 5--9 pairs, eucamptodromous, occasionally brochidodromous, briefly running alongside midrib before arching at 40-50° from midrib, upper surface veins flat, glabrous, lower surface veins flat, glabrous. Tertiary veins transverse to transverse reticulate, occasional parallel or reticulate veins. Leaf margin slight revolute. Inflorescence amongst leaves at tips of branches, often densely clustered, ca. 4--10 flowers. Bracts semi-persistent, few, brown hairs. Pedicel 5 mm long, angular to flattened, grooved, sparse adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 2--3 X 1.5--2 mm, apex obtusely-acute, outer surface sparse golden hairs, or wrinkled and glabrous, inner-surface dense golden hairs, margin scarious, fimbriate, glabrous, inner whorl of calyx lobes, ovate-triangular-rounded, 2--2.5 X 1--2 mm, apex rounded or obtuse, margin scarious, fimbriate, glabrous, outer surface dense adpressed golden hairs, inner surface sparse golden hairs. Corolla 2 mm long, ovate, apex toothed, not reflexed in anthesis, glabrous. Stamens 12, in two whorls, inserted 0.5 mm from base, filaments 1 mm long, anthers oblong, apex rounded, dorsifixed close to distal end, sparse golden hairs. Ovary ellipsoid, 1 X 0.6--0.7 mm, 6-locular, glabrous or golden hairs on upper half, lower half glabrous. Style 1.5--2 mm long, glabrous. Fruit ellipsoid, 1.2 X 0.7 cm, glabrous, style persistent to 2 mm long. Seed ellipsoid, 11 X 5 X 4 mm, colour unknown, narrow scar, 2 mm wide, scar covers less than ½ seed surface.

Unseen: seed. Described from van Royen (1960).

Habitat. Kerangas forest, peat swamp forest, freshwater swamp forest, on white sand, peat or alluvial soils.

Altitude. 0 to 300 m.

Distribution. Borneo, Peninsular Malaysia, Sulawesi (and possibly Sumatra, the Philippines, New Guinea and Indo-China, in van Royen, 1960 and Chai & Yii, 2002).

Fig. 39. Map of P.ridleyi collection locations across range In Brunei: Brunei-Muara district: Berakas Forest Reserve. Temburong district: Bukit Belalong.

Vernacular names. Nyatoh, nyatoh batu, nyatoh jangkar, nyatoh merah, bitis.

Uses. Timber.

Proposed IUCN conservation status. Least concern (LC). (see chapter 5 ).

Key characters. Glabrous leaves. Inner whorl of calyx lobes more densely hairy than outer calyx whorl (this is unusual, the opposite is seen in other species).

Morphologically similar species

P.walsurifolium also has glabrous leaves that are elliptic to obovate and of similar length. P.walsurifolium can be distinguished by its frequently longer petiole to 2.5 cm long, greater angle of secondary veins at 60--70⁰, and longer style to 8 mm long.

Specimens seen. (i=images seen)

INDONESIA. Sumatra. Soepadmo 199. (E!); Soepadmo 207 (E!).

PENINSULA MALAYSIA. Selangor. Corner 33958 (K!); Ng FRI5435 (K!). Singapore. Ridleyi 3591a (K!).

BRUNEI. Brunei-Muara district: Berakas Forest Reserve. Ashton 1007 (BRUNi). Temburong district: Bukit Belalong. Ashton BRUN416 (Ki, KEPi).

15. Palaquium rioense H.J.Lam. Bull. Jard. Bot. Buitenzorg 111. 7: 89 (1925).

No synonyms.

Type: Hortus Bog. IV. C. 23 (holotype BO, isotype US).

Tree to 42 m tall, dbh unknown, buttresses unknown, bark brown, slightly rough, inner bark and sapwood unknown. Twigs 3--6 mm diameter, subterete, angular towards tips, sulcate,patches of horizontal cracking, numerous leaf scars, mostly glabrous, short brown woolly hairs towards tips. Stipules caducous, narrowly ovate-triangular, to 10 mm long, outer surface adpressed hairs, inner glabrous. Leaves well-spaced along twigs. Petiole 1.5--2 cm long, angular, woolly greyish or golden hairs, glabrescent, closed adaxial groove. Leaf blade (5--)8--11 X 3--5 cm, chartaceous, elliptic to obovate, apex attenuate to short obtusely acuminate, rarely rounded or slight emarginate, base cuneate or obtuse, sometimes oblique, very shortly decurrent, upper surface dries dark chocolate-brown, glabrous or sparse whitish hairs above, dense adpressed golden hairs below. Midrib sunken, glabrous or sparse whitish hairs above, raised, adpressed golden hairs below. Secondary veins 14--18 pairs, eucamptodromous, sometimes faintly brochidodromous, briefly running alongside midrib before arching at 60--70° from midrib, upper surface veins slightly raised, glabrous, lower surface veins raised, adpressed golden hairs, same colour as blade. Tertiary veins transverse to transverse-reticulate. Leaf margin not-revolute. Inflorescence from tubercles above leaf scars, below leaves, ca. 4--8 flowers. Bracts persistent, many, orange-brown hairs. Pedicel 10 mm long, angular to flattened, adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 3 X 2 mm, apex obtusely-acute, outer surface dark-golden hairs, inner surface glabrous, inner whorl of calyx lobes ovate, 2.5 X 1.5 mm, apex acute, margin scarious, slight fimbriate, glabrous, outer surface light-golden hairs, inner surface glabrous. Corolla 5--6 mm long, narrowly-ovate, apex obtuse, toothed, not reflexed in anthesis, golden hairs near base and tips on both surfaces. Stamens 12, in two whorls, inserted 1 mm from base, filaments 1.5 mm long, golden hairs at base, outer filaments straight, inner bent, anthers sagittate, 2 mm long, apex pointed, bifid or blunt. Ovary globose, 1 X 1 mm, 6-locular, dense golden hairs on upper half, lower half glabrous. Style to 12 mm long, glabrous. Fruit obovoid, 1.2 X 1.5 cm, glabrous, stub of style persistent. Seed obpyriform, size unknown, colour unknown, scar covers ⅓ seed surface.

Unseen characters: fruit and seed. Described from van Royen (1960), and Chai & Yii (2002).

Habitat. Montane and hill forests, montane shale ridges.

Altitude. 1200-3000 m.

Distribution. Borneo, (and possibly Riouw, in van Royen, 1960).

Fig. 40. Map of P.rioense collection locations across range In Brunei. No records found.

Vernacular names. Nyatoh, nyatoh rian, getah keras, pau.

Uses. Unknown.

Proposed IUCN conservation status. Critically Endangered (CR). (see chapter 5 ).

Key characters. Leaves elliptic to obovate, leaf base very shortly decurrent, dense adpressed hairs on lower leaf surface. Long glabrous style to 12 mm.

Morphologically similar species. The obtuse, shortly decurrent leaf base in addition to the leaf shape make confusion with other species unlikely.

Notes. Hasan and Ashton’s (1964) checklist is the only record of P.rioense in Brunei. It is described as locally frequent on montane shale ridges. If in Brunei it is only likely to occur in the Bukit Pagon area due to its altitudinal range and montane shale substrate. Most known specimens are from Mt Kinabalu, Sabah.

Specimens seen. (i=image seen)

INDONESIA. Riouw. Hortus Bog. IV. C. 23 (BOi).

MALAYSIA. Borneo. Sabah: Clemente 6218 (Li); Sinclair 8973 (E!).

BRUNEI. No records found.

16. Palaquium rivulare H.J.Lam. Bull. Jard. Bot. Buitenzorg 111. 8: 403 (1927).

No synonyms.

Type: Endert 3021 (holotype BO, isotype L).

Tree to 20 m tall, 40 cm dbh, narrow buttresses to 10 m high, 75 cm long, bark pale-brown, smooth, inner bark unknown, sapwood pale-brown. Twigs 3--7mm diameter, terete, mostly glabrous, hairs toward tips. Stipules caducous, oblong, 0.9--1.4 cm long, sparse hairs on outer surface, inner glabrous. Leaves well-spaced along twigs. Petiole 0.9--2.6 cm long, angular, sparsely golden tomentose, glabrescent, slight adaxial groove. Leaf blade 23--46 X 8--14 cm, chartaceous, oblong, apex acuminate, base rounded to truncate, sometimes slightly oblique, not decurrent, glabrous on both surfaces. Midrib sunken, glabrous above, raised, rounded, sparse brown hairs or glabrous below. Secondary veins 18--22 pairs, eucamptodromous, occasionally brochidodromous, briefly running alongside midrib before arching at 50--60° from midrib, upper surface veins slightly raised, glabrous, lower surface veins raised, glabrous. Tertiary veins transverse. Leaf margin not revolute. Inflorescence axillary, ca. 5--8 flowers. Bracts semi-persistent, few, hairs on outer surface. Pedicel (3--)5--6(--8) mm long, angular, golden hairs, glabrescent. Flowers. Calyx outer whorl of calyx lobes ovate- triangular, 4--5 mm long, apex obtusely acute, outer surface golden hairs, inner surface glabrous, inner whorl of calyx lobes ovate-rounded 4--5 mm long, apex rounded, margin scarious, fimbriate, glabrous, outer surface golden hairs, inner surface glabrous. Corolla 4-- 4.5 mm long, ovate-oblong, apex obtuse, not reflexed in anthesis, fimbriate, golden hairs along mid-line, otherwise glabrous. Stamens 18--21, whorls unknown, 3.5 mm long, inserted at base, filaments 0.5--1.5 mm long, anthers oblong 3--4.5 mm long, apex acuminate, golden hairs. Ovary conical, 0.5 X 2 mm, 6-locular, golden hairs. Style 3--4 mm long, glabrous. Fruit unknown. Seed unknown.

Unseen characters: all. Described from protologue, image of type and van Royen (1960).

Habitat. Mixed dipterocarp forest, alluvial forest, on rocky, sandy, clayey, limestone or alluvial soils.

Altitude. Low.

Distribution. Endemic to Borneo.

Fig. 41. Map of P.rivulare collection locations across range In Brunei. Temburong district: Bukit Patoi.

Vernacular names. Nyatoh.

Uses. Unknown.

Proposed IUCN conservation status. Vulnerable (VU). (see chapter 5 ).

Key characters. Large oblong leaves, 27 to 46 cm long, acuminate apex. Stamens 18-21.

Morphologically similar species. P.sericeum has similarities of truncate leaf base that is not decurrent, it can be distinguished from P.rivualre by its shorter leaves (10--22 cm long) with dense adpressed hairs on the lower surface.

Notes. The leaf size and shape of this species makes it distinctive. Images of herbarium specimens would be easy to identify, but there are very few known specimens, and even fewer images.

No previously cited material for Brunei.

Specimens seen: (i=images seen)

INDONESIA: Borneo: Kalimantan. Endert 3021 (BOi, Li); Kostermans 9701 (Li).

BRUNEI: Temburong district: Bukit Patoi. Ashton 3850 (BRUNi).

17. Palaquium rostratum (Miq.) Burck. Ann. Jard. Bot. Buitenzorg 5: 39 (1885).

Basionym: Isonandra rostrata Miq., Fl. Ned. Ind., Eerste Bijv.: 581 (1861). Homotypic Synonym: Croixia rostrata (Miq.) Baehni, Boissiera 11: 109 (1965). Heterotypic Synonyms: Palaquium bancanum Burck, Ann. Jard. Bot. Buitenzorg 5: 43 (1885); Palaquium linggense Burck, Ann. Jard. Bot. Buitenzorg 5: 42 (1885). Type: Teysmann s.n. (BO).

Tree to 45(--60) m tall, 135 cm dbh, buttressed, size unknown, bark greyish-brown, fissured, inner bark and sapwood unknown. Twigs 3-8 mm diameter, subterete to angular, sulcate, numerous leaf and tubercle scars, mostly glabrous, orange-brown tomentose at tips. Stipules caducous, ovate-triangular, 3--4 mm long, greyish-brown tomentose. Leaves loosely clustered at tips of twigs. Petiole 1--2.5 cm long, flattish or ridged above, angular, ridged below, no adaxial groove, glabrous. Leaf blade 7--13 X 4--6 cm, coriaceous, spathulate to elliptic to obovate to oblong, apex rounded, short attenuate tip, sometimes emarginate, base cuneate, decurrent, glabrous on both surfaces. Midrib slightly sunken or flat or slightly raised, glabrous above, raised, ridged, glabrous below. Secondary veins 14--20 pairs, brochidodromous, briefly running alongside midrib before arching at 70-80° from midrib, glabrous. Tertiary veins parallel-reticulate. Leaf margin slight revolute or not. Inflorescence from tubercles above leaf scars or axillary, ca. 4--6 flowers. Bracts semi-persistent, few, orange-brown hairs. Pedicel 2--10 mm long, angular to flattened, grooved, adpressed golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 2--2.5 X 1.5 mm long, apex obtusely acute, outer surface reddish-brown hairs, inner surface glabrous, inner whorl of calyx lobes ovate-triangular, 2.5--3 X 1.5 mm, apex blunt or pointed, margin scarious, fimbriate, glabrous, outer surface golden hairs, inner surface glabrous. Corolla 4 mm long, reflexed in anthesis, tip and margins fimbriate, outer surface long golden hairs, inner surface golden hairs on lower half only. Stamens 12, in two whorls, stamens opposite petals inserted higher than alternepetalous stamens, filaments 0.5--1.5 mm long, golden hairs between bases, anthers ovoid, 0.6--1.1 mm long, apex rounded, connective not prolonged, golden hairs between thecae. Ovary discoid, 0.5 X 1.5 mm, 6-locular, golden hairs on upper half, lower half glabrous. Style 3mm long, golden hairs at base, extending ½ way along style. Fruit ellipsoid, 2 X 1 cm, sparse golden hairs, brown scales at base, glabrescent, stub of style persistent. Seed ovoid, 1--2.3 X 6--9 mm, brown, glossy, scar covers ½ seed surface.

Unseen: seed. Described from van Royen (1960).

Habitat. Freshwater swamp forest, mixed dipterocarp forest, kerangas forest.

Altitude. 0 to 800 m.

Distribution. Borneo, Java, Thailand, Peninsular Malaysia, the Philippines (and possibly Sumatra, Riouw and Sulawesi, in van Royen, 1960).

Fig. 42. Map of P.rostratum collection locations across range In Brunei: Belait district: Andalau Forest Reserve. Temburong district: Ulu Ropan; Kuala Sekurop.

Vernacular names. Njatoh baian, njatoh baitis, njatoh geronong.

Uses. Fruit, edible oil from seeds, timber-attractive wood.

Proposed IUCN conservation status. Least concern (LC). (see chapter 5 ).

Key characters. Secondary veins brochidodromous, tertiary veins parallel-reticulate. Corolla lobes reflexed in anthesis. Stamens 18-21.

Morphologically similar species. Based on images P.dasyphyllum and P.rostratum could be confused due to similar leaf shape. From herbarium specimens the two can be distinguished by tertiary veins, which for P.dasyphyllum are transverse-reticulate, and for P.rostratum are parallel-reticulate.

Specimens seen. (i=image seen)

INDONESIA. Lingga. Teysmann s.n. (BOi).

MALAYSIA. Peninsula Malaysia. Bell & Moh. n.s. (K!); Kiah 37117 (K!); King 6509 (K!); Molios 6019 (K!); Motan 98828 (K!); Ridley 6527; Symington 43542 (K!); Whitmore FRI12425 (Ki, KEPi).

BRUNEI. Belait district: Andalau Forest Reserve. Smythies SAN17509 (KEPi). Temburong district: Ulu Ropan. Ashton BRUN 5845(Ki); Kuala Sekurop. Ashton BRUN 742 (KEPi).

18. Palaquium sericeum H.J.Lam. Bull. Jard. Bot. Buitenzorg 111, 7:53 (1925).

Homotypic Synonym: Palaquium sericeum var. autocalyx H.J.Lam, Bull. Jard. Bot. Buitenzorg, III, 7: 55 (1925), nom. inval.

Type: Jaheri 716 (BO).

Tree to 18 m tall, 25 cm dbh, slightly buttressed or not, bark pale-brown to grey, smooth or shallowly fissured, inner bark pale-brown, sapwood whitish-brown. Twigs 1.5--3 mm diameter, sub-terete to angular, sulcate, few leaf scars, dense light-brown or golden hairs towards tips, older twigs glabrescent. Stipules persistent, linear, in pairs, to 11 mm long, dense light-brown or golden adpressed or simple hairs. Leaves well-spaced along twigs. Petiole 0. 3--0.7 cm long, angular, sulcate, no adaxial groove, dense adpressed or simple hairs, glabrescent. Leaf blade (6--)10--22 X 3--9 cm, chartaceous, elliptic to oblong to oblanceolate, apex acuminate, tip 0.3--1.5 cm long, occasionally obtuse, end of tip sometimes bilobed, base sub-cordate to truncate, not decurrent, glabrous or dense whitish hairs at base, dries dark chocolate-brown above, dense adpressed silvery hairs, sometimes interspersed with simple golden hairs below. Young leaves dense adpressed silvery hairs and simple golden hairs on both surfaces. Midrib sunken, glabrous or with hairs from base to half way above, raised, angular, wide, adpressed and/or simple golden to silvery hairs below. Secondary veins 9--18 pairs, eucamptodromous, occasionally brochidodromous, briefly running alongside midrib before arching at 50--60⁰ from midrib, upper surface veins slightly sunken, glabrous, lower surface veins raised, adpressed silvery and simple golden hairs. Tertiary veins transverse. Leaf margin not revolute. Inflorescence axillary, ca. 2--7 flowers. Bracts semi- persistent, few, light golden hairs. Pedicel 20 mm long, angular, grooved, silvery to golden hairs. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 3.5 X 3mm, apex obtuse, outer surface dense silvery and golden hairs, inner surface glabrous, inner whorl of calyx lobes ovate-rounded, 2.5--3.5 mm, apex rounded, margin scarious, fimbriate, wide, glabrous, outer surface adpressed golden hairs, inner surface verrucose, glabrous. Corolla 6.5 mm long, ovate-triangular, apex obtuse, not reflexed in anthesis, indumentum unknown. Stamens 12, whorls unknown, inserted 2 mm from base, filaments 0.5 mm, glabrous, anthers oblong, 2 mm long with 1 mm long pointed tip, basifixed, glabrous. Ovary conical to globose, 2 X 1 mm, 7-locular, lower half golden-brown hairs, upper half glabrous. Style 5.5 mm long, hairs at base then glabrous. Fruit ellipsoid, 2 X 1.5 cm, yellowish to brownish-green, drying brown, golden-brown scales, style persistent, to 3 mm long or broken. Seed ellipsoid, 1.5 X 1 cm, colour unknown, scar covers ⅓ seed surface.

Unseen: seed. Described from Chai & Yii (2002).

Habitat. Mixed dipterocarp forest on sandy and clay soils, alluvial forest, sometimes found in limestone forest

Altitude. 0 to 200 m

Distribution. Endemic to Borneo.

Fig. 43. Map of P.sericeum collection locations across range In Brunei. Belait district: Bukit Sawat. Bukit Teraja. Labi. Mendaram Waterfall. Temburong district: Kuala Belalong.

Vernacular names. Nyatoh.

Uses. Unknown.

Proposed IUCN conservation status. Least concern (LC). (see chapter 5 ).

Key characters. Persistent pairs of stipules, leaf apex with acuminate tip to 15mm long which is frequently bilobed, leaf base truncate to sub-cordate, not decurrent, lower leaf surface with dense adpressed silvery hairs, sometimes interspersed with simple golden hairs, upper leaf surface dries dark chocolate- brown.

Morphologically similar species. P.rivulare has similarities of truncate leaf base that is not decurrent, it can be distinguished from P.sericrum by its much longer leaves (23--46 cm long) which are glabrous.

Specimens seen. (i=image seen)

INDONESIA. Borneo. Kalimantan. Jaheri 716 (Boi); Tuke P1223 (E!).

MALAYSIA. Borneo. Sabah: Wong WKM2343 (E!). Sarawak: Lee S39815(E!).

BRUNEI. Belait district: Bukit Sawat. Watu Awok BRUN21885 (BRUNi); Bukit Teraja. Ahmad et al. BRUN16819 (BRUNi, SANi); Dransfield JD7024 (BRUNi); Wong WKM1568 (BRUNi, Ki, KEPi). Labi. Ariffin BRUN18041 (BRUNi); Ariffin BRUN20341 (BRUNi); Johns 7440 (BRUNi, KEPi); Salleh 16244 (BRUNi, Ki, SANi). Mendaram Waterfall. Dransfield JD6555 (BRUNi, Ki, KEPi, SANi); Kirkup 360 (BRUNi, Ki); Said BRUN16573 (BRUNi, SANi, SINGi). Temburong district: Kuala Belalong. Hemingway 169 (BRUNi); Hemingway 197 (BRUNi).

19. Palaquium stipulare Pierre ex Dubard. Bull. Soc. Bot. France 56 (16): 21 (1909).

Heterotypic synonym: Palaquium richardsii Griffoen & H.J.Lam, Bull. Misc. Inform. Kew 1936: 17 (1936).

Type: Beccari 1549 (P).

Tree to 24 m tall, dbh 180 cm, buttresses to 120 cm high, 90 cm long, bark light-brown to brownish-grey, shallowly fissured, flaky, inner bark and sapwood pale yellow. Twigs 6--8 mm diameter, subterete to angular, sulcate, numerous leaf and tubercle scars, enlarged lenticels/verrucose in places, adpressed orange-brown hairs towards tips of twigs, older twigs greyish-brown tomentose, glabrescent. Stipules caducous, scale-like, 8 X 2 mm, adpressed orange-brown hairs on outer surface, inner glabrous. Leaves well-spaced along twigs. Petiole 2--4 cm long, angular to flattened, some horizontal cracks, no clear adaxial groove, adpressed or woolly orange-brown hairs, glabrescent. Leaf blade 15--26 X 9--14 cm, chartaceous to coriaceous, obovate to oblanceolate, apex rounded to slight emarginate, base sub-truncate to cuneate to sub-cordate, shortly decurrent or not decurrent, glabrous, or sparse whitish hairs above, glabrous or occasional golden hairs below. Midrib slightly raised to flat to slightly sunken, greyish-brown adpressed or tomentose hairs, glabrescent above, raised, sparse golden hairs, glabrescent below. Secondary veins 10--19 pairs, eucamptodromous, occasionally brochidodromous, briefly running alongside midrib before arching at 50--60⁰ from midrib, upper surface veins slightly raised, glabrous or sparse greyish-brown hairs, lower surface veins raised, golden hairs, glabrescent. Tertiary veins transverse to transverse-reticulate. Leaf margin not revolute, sparse golden hairs or glabrous. Inflorescence axillary or above leaf scars, ca. 5 flowers. Bracts semi-persistent, orange-golden hairs in middle, margins glabrous. Pedicel 8--10 mm, angular, grooved, dense orange-golden hairs, glabrescent patches. Flowers. Calyx outer whorl of calyx lobes ovate-triangular, 2.5 X 2.5 mm, apex obtusely- acute, outer surface dark orange-golden hairs, inner surface glabrous, inner whorl of calyx lobes ovate-triangular, 3 X 1.5 mm, apex blunt, margins scarious, wide, fimbriate, glabrous, outer surface adpressed light-golden hairs, inner surface glabrous. Corolla 20 mm long, ovate, apex blunt, fimbriate, outer surface slight verrucose, sparse golden hairs, inner surface glabrous. Stamens 20, whorls unknown, inserted at base, filament to 1mm long, anthers 1.5-- 2 mm long, ovate-triangular, pointed tip, long golden hairs on non-connective side, verrucose. Ovary ovoid, 2 X 1.5 mm, 6-locular, dense golden hairs. Style to 10 mm long, hairs at base then glabrous. Fruit globose, 2--2.7 cm, sparse hairs, glabrescent, style persistence unknown. Seed unknown.

Unseen: fruit and seed. Described from Chai & Yii (2002).

Habitat. Lowland mixed dipterocarp forest, on clay and sandy soils, also grows on limestone hills.

Altitude. 0 to 300 m.

Distribution. Endemic to Borneo.

Fig. 44. Map of P.stipulare collection locations across range In Brunei. Belait district: Sungai Mau.

Vernacular names. Nyatoh, nyatoh babi, nyatoh terentang.

Uses. Unknown.

Proposed IUCN conservation status. Vulnerable (VU). (see chapter 5 ).

Key characters. Leaves glabrous, obovate to oblanceolate, 15-26 cm long, base sub-truncate to cuneate to sub-cordate, not decurrent. Stamens 20.

Morphologically similar species. P.obtusifolium also has obovate leaves with rounded to sub-emarginate apex, and cuneate to sub-truncate base. It can be distinguished from P.stipulare by its shorter petiole (to 1.5 cm long) and lower number of secondary veins with 10--11 pairs.

Notes. No previously cited material for Brunei.

Specimens seen. (i=image seen)

MALAYSIA. Borneo. Sarawak: Anderson S31631 (E!); Anderson S25606 (SANi); Beccari 1549 (Pi); Chai S37358 (KEPi); Erwin & Chai S27446 (KEPi, SANi); Illias S28094 (E!); Illias S37968 (KEPi, SANi); Jugah S23707 (SANi); Mamit 37464 (KEPi, SANi); Richards 2605 (Ki).

BRUNEI. Belait district. Labi Road. Ashton BRUN34 (BRUNi, Ki), Sungai Mau. Kalat & Niga ARK94 (BRUNi).

20. Palaquium walsurifolium Pierre ex Dubard. Bull. Soc. Bot. France 56 (16): 22 (1909).

No synonyms. Sometimes as Palaquium walsuraefolium.

Type: Beccari 557 (P).

Tree to 37 m tall, dbh unknown, with stilt roots, bark brown, smooth, inner bark and sapwood unknown. Twigs 2--3.5 mm diameter, unknown if sulcate, leaf scars unknown, mostly glabrous, greyish to orange-brown tomentose towards tips. Stipules semi-persistent, triangular-lanceolate, to 3 mm long, outer surface orange-brown tomentose, inner glabrous. Leaves loosely clustered at tips of twigs. Petiole 1--2.5 cm long, angular, orange-brown or greyish tomentose, glabrescent, adaxial groove or flat. Leaf blade 4--9.5 X 2--4.5 cm, coriaceous, elliptic-obovate or obovate, apex rounded or with short obtuse tip, base cuneate, decurrent, young leaves have golden hairs, soon becoming glabrous on both surfaces. Midrib slightly sunken, glabrous above, raised, rounded, glabrous below. Secondary veins 7--10 pairs, eucamptodromous, briefly running alongside midrib before arching at 60--70⁰ from midrib, upper surface veins sunken, glabrous, lower surface veins raised, glabrous. Tertiary veins transverse. Leaf margin not revolute. Inflorescence axillary, ca. 2--5 flowers. Pedicel 3--7 mm long, terete, orange-brown tomentose. Flowers. Calyx outer whorl of calyx lobes ovate-rounded, 2.5--3.5 X 2--2.5 mm, apex rounded, outer surface orange-brown or greyish hairs, inner surface glabrous, inner whorl of calyx lobes elliptic, 2.5--3.5 X 2--2.5 mm, apex obtusely-acute, margin scarious, fimbrate, glabrous, outer surface orange-brown or grey hairs, inner surface glabrous. Corolla 6-lobes, 6--7 mm long, ovate-elliptic, apex obtuse, not reflexed in anthesis, glabrous, or sparse hairs on inner surface. Stamens 12, in two whorls, point of insertion unknown, filaments 2.5 mm long, anthers ellipsoid, 1--1.5 mm long, apex rounded or bifid, glabrous. Ovary discoid or globose, 0.5--1 X 1--1.5 mm, 6-locular, brownish tomentose. Style 5--8 mm long, glabrous. Fruit globose to ellipsoid, 2 X 1.5 cm, glabrous, persistent stub of style. Seed ellipsoid, 7--14 X 5--7 mm, colour unknown, scar covers ⅓ seed surface.

Unseen characters: all. Described from protologue, image of type, van Royen (1960) and Chai & Yii (2002).

Habitat. Peat swamp forest, freshwater swamp forest.

Altitude. Low.

Distribution. Borneo. (and possibly Peninsular Malaysia and Sumatra, in van Royen, 1960).

Fig. 45. Map of P.walsurifolium collection locations across range In Brunei: Temburong district: Kuala Belalong.

Vernacular names. Nyatoh, nyatoh batu, nyatoh nangka, nyatoh jangkar.

Uses. Unknown.

Proposed IUCN conservation status. Near Threatened (NT). (see chapter 5 ).

Key characters. Leaves elliptic-obovate or obovate, apex rounded or with short obtuse tip, adult leaves are glabrous, secondary vein angle of 60--70⁰.

Morphologically similar species. P.herveyi and P.ridleyi are both similar. P.herveyi can be distinguished from P.walsurifolium by the sparse golden hairs on lower leaf surface, lower secondary vein angle of 40--50˚ and corolla is shorter at 4 mm long. P.ridleyi differs with shorter petioles to 1.5 cm long, lower angle of secondary veins of 40--50⁰, and shorter style to 2 mm long.

Notes. No previously cited material for Brunei.

Specimens seen. (i=images seen)

MALAYSIA. Borneo. Sarawak: Beccari 557 (Pi); Lee S46453 (KEPi, SANi).

BRUNEI. Temburong district: Kuala Belalong. Smythies, Wood, Ashton SAN17076 (KEPi).

Excluded Palaquium species for Brunei

An excluded but potential new record for Brunei is P.beccarianum. A sterile specimen is in BRUN, Unknown L1449, which was determined by van Royen in 1960.

Aside from the collector number, there is no collector name or location. It appears to be a collected in Brunei, but further evidence of its collection location is needed before it can confidently be added as a new record for Brunei.

Chapter five

5. Conservation assessmnts for Palaquium of Brunei

5.1 Conservation issues in Brunei

Oil is the main source of revenue for the country which, unlike the rest of Borneo, has spared much of the forests from exploitation. Agricultural land use is also low in Brunei, with most products being imported. Illegal logging is not considered a major problem.

A potential threat to the forests of Brunei is at the border with neighbouring Sarawak. Only a small region of the border has protected forest on either side (south-west Tutong district) and the majority has no protection on the Sarawak side of the shared border.

Illegal logging encroaching into the Brunei forests is a threat which may become a greater issue as Sarawak forests become more depleted.

While threats to forests in Brunei are generally low, there are threats from development and industry. The most developed district of Brunei is Brunei-Muara, it is the least forested and most populated. Much of the coastal regions of Belait district and Tutong district have also been deforested and developed. Any expansion of these urban areas would threaten nearby forest.

Industry, especially sand mining, is a threat to forests especially the peat swamp forests of Belait district. It has been estimated that 20% of Brunei's peat swamp forests have been disturbed by activities such as sand mining (Davies, 2000).

Other past damage to forests in Brunei include road construction and overland water pipelines. The road system is relatively limited and generally restricted to coastal regions with access to much of the rest of the country via rivers. The water pipelines are in place to transport water to the oil distilleries in northern Belait district. Both have involved forest clearance, causing fragmentation and the creation of corridors enabling invasive species to move into new areas of forest.

Fig. 46. Image of cleared peat swamp forest for pipelines in Belait district. Disparity in land use along the borders is another threat. Clearly seen in places as a sharp distinction between primary forest within Brunei suddenly switching to cleared areas of forest where the land is often converted to oil palm plantations in Sarawak. This dramatic change in land use causes forest fragmentation and degrades the forest edges.

An example can be seen in the satellite image below showing part of the border in north- eastern Brunei. Differences in vegetation can be seen in the darker forested area of Brunei above the white line, below the white line is cleared forest in Sarawak.

Fig. 47. Image of changing land use at border with Sarawak (Image from Protected Places, 2013) Peat swamp forests that occur in Brunei are globally a seriously threatened habitat (Ashton, 1998). The most extensive peat swamps of Brunei are in Belait district. Peat swamp formations are sensitive to changes in water levels. Any disturbance to a peat dome may affect the water table.

This is a threat in Brunei where peat swamp forests cleared across the border in Sarawak are part of a shared peat dome within Brunei. Leading to forest degradation, invasive species entering the ecosystem and increased risk of fire as the peat dries out. Fire is considered the biggest threat to peat swamp forests in Brunei, extensive fires occurred during an exceptionally dry period in 1998 (Davies, 2000).

If the widespread degradation and clearance of forests in the rest of Borneo continues, the less threatened forests of Brunei will become even more important. In time they may be one of the few remnants of the once densely forested island, and are likely to contain numerous anthropogenic endemics (Henrot et al, 2013). The extent of forest loss since 1950 is illustrated in the series of maps of Borneo below, where green represents forested land (see fig. 48.).

Fig. 48. Deforestation across Borneo 1950-2020 (Image from Ahlenius, 2007)

5.2 Forest reserves Forest reserves in Brunei are designated either for protection as conservation forests or for sustainable timber extraction as production forests. Both designations ensure the land will remain forested, though their management and levels of disturbance are different. Protected forests cover 16.2% of Brunei’s land mass, 8% of which is the country’s only National Park, Ulu Temburong, 3.2% are production forests, and 5% are conservation forests and research reserves (Wong & Kamariah, 1999).

A single forest reserve may have different compartments designated either as conservation forest or production forest (Henrot et al, 2013). This is the case in the Andalau Forest Reserve in Belait district.

A new informal category of 'Lower Risk-conservation dependent' (LR cd) has been suggested specifically for endemic flora in Brunei with at least one population in a protected forest (Henrot et al, 2013). Endemics within conservation forests are less threatened by disturbance and poaching, though their increased survival chances are strongly linked to the protection

65 status of the forest they are in. Endemics not in protected forest would be placed in the critically endangered (CR) category.

Although not relevant to this study due to the lack of Palaquium endemics, it does highlight the importance of protected forests. Location of a species within a conservation reserve rather than a production reserve or unprotected forest is significant to its survival chances.

Fig. 49. Image showing protected forests in Brunei (highlighted in blue) (Image from GEOcat, 2013)

5.3 IUCN conservation assessments

The International Union for Conservation of Nature (IUCN) Red List was set up in 1963 to assess the risk of extinction of all species. Assessing the conservation status of a species can help promote awareness of threats to biodiversity; influence policy making at both a national and international level; and provide scientifically based information to guide conservation efforts.

IUCN criteria has been used for each species to evaluate whether it is threatened and which of the following categories it belong to:

Fig. 50. IUCN Red List categories (IUCN, 2013)

EX and EW were not used as there is no evidence of extinctions. NE was not used as each species has been evaluated. Each of the species has been placed in one of the following categories: CR, EN, VU or LC.

5.4 Distribution data

Distribution data was exported from the PAMDE database at Royal Botanic Garden Edinburgh into GeoCAT (Geospatial Conservation Assessment Tool) (Bachman et al, 2011) to calculate the extent of occurrence (EOO) and area of occurrence (AOO) for each species. GeoCAT was also used to identify whether collections were from protected forest.

The PADME data base contains about 52 000 Sapotaceae distribution records for south-east Asia from the herbaria of E, K, L, BRUN, SING, KEP and SAN.

Distribution data across a species entire distribution (not just Brunei) was taken into consideration when deciding conservation status. The limitations of this data was also taken into account, especially that some areas are undercollected and thus species may be present but just not yet recorded from an area. Within Borneo, Kalimantan is under collected whereas Sabah is the most collected region.

The following assessments take into account the whole range of the species as represented in the PADME database, and use the criteria set out by IUCN.

5.5 Palaquium conservation assessments

1. Palaquium calophyllum

Least concern (LC)

Reasons. Over 200 collections across Borneo, mostly from Sabah and Sarawak, including many recent collections. It grows in the widespread habitat of mixed dipterocarp forest and is also known from secondary forest, indicating an ability to withstand some disturbance.

Range. Borneo (and possibly Sumatra, the Philippines, the Moluccas, New Guinea, in Lam 1925, 1927).

Habitat. Lowland mixed dipterocarp forest and secondary forest.

Threats. Three known locations in Brunei, one is in protected forest of Tasek Merimbun ASEAN Heritage Park, Tutong district while two locations are not protected. The Temburong district location appears undisturbed while the Belait district site is close to disturbed forest and the major road Jalan Labi (observations from satellite images). Aside from these disturbances to the forest of Belait district, threats also come from outside of Brunei where forest disturbance and clearance are widespread.

Collections in Brunei: Eight collections, from the 1950's to 2007.

Notes. No collection data for Sumatra, Borneo, the Philippines, the Moluccas and New Guinea where it is also thought to occur. More collections needed to confirm its range.

Fig. 51. Map of P.calophyllum collections showing EOO

Fig. 52. Map of collection locations of P.calophyllum in Brunei 2. Palaquium cochleariifolium

Endangered (EN)

EN B2ab(iii)

B2. AOO = 64 km², <500 km²; a. severely fragmented; b(iii). Continuing decline in quality of habitat.

Range. Endemic to Borneo

Habitat. Peat swamp forest.

Threats. Industry, especially sand mining is thought to have degraded peat swamps of Belait district, also fragmentation by roads and pipelines that cut through parts of Belait's forests (see notes below). Threats to these forests from outside Brunei is seen where they occur on shared peat dome formations with neighbouring Sarawak. This habitat is sensitive to fluctuations in water table levels caused by deforestation. Drainage of any part of the shared dome causes drying of the peat which brings the risk of fire.

Collections in Brunei. Nine collections from three sites in Belait district, plus three from unknown localities, none are in protected forests. All known collections were in the 1950s. Three undated specimens determined by van Royen in 1960.

Notes.New collections needed to confirm it is still present in Brunei.

One of the recorded locations of P.cochleariifolium in Brunei is close to a major over ground pipeline which transports water to the oil refining centre in Seria. Building of the pipeline has destroyed part of the forest, and caused fragmentation and disturbance within the remaining forest.

It also creates a corridor for invasive species to travel along and then penetrate into the forest interior.Invasive tree species able to grow in peat swamp conditions do not have the thick lignified leaves of the native peat swamp species (from discussions with Universiti Brunei Darussalam associates in Brunei), their leaves are quick to decompose and so contribute little to the peat accumulation process, in time this could threaten the peat swamp forest ecosystem.

Fig. 53. Map of P.cochleariifolium collections showing EOO

Fig. 54. Map of collection locations of P,cochleariifolium in Brunei

3. Palaquium dasyphyllum

Least concern (LC)

Reasons. In Brunei only three occurrences recorded. But taking the whole of P.dasyphyllum's range into account, it does not belong in a threatened category. With over 200 occurrences across northern Borneo and EOO of 875 144.19 km².

Occurs in a widespread habitat and approximately ten of its known locations are in protected forest. Regular collections made from the rest of Borneo between 1950's and 2000.

Range. Borneo (and possibly Riouw, van Royen 1960 cites 1 collection).

Habitat. Hill mixed dipterocarp forest and montane forest.

Threats . There is no obvious threat to this species within Brunei. One known location is in Ulu Temburong National Park the others in apparently undisturbed forest (as seen from satellite map images) to the north of the National Park. Threats are more likely outside of Brunei due to widespread forest degradation and clearance.

Collections in Brunei. Three collections in the 1950's in Temburong district.

Fig. 55. Map of P.dasyphyllum collections showing EOO

Fig. 56. Map of collection locations of P,dasyphyllum in Brunei

4. Palaquium decurrens

Vulnerable (VU)

VU B2ab(iii)

B2. AOO = 52 km², <2000 km²; a. number of locations ≤10; b(iii). Continuing decline in area, extent or quality of habitat.

Range. Endemic to Borneo.

Habitat. Mixed dipterocarp forest, 300 to 600 m altitude.

Threats. The one collection from Brunei is in unprotected lowland forest, possibly degraded (as seen from satellite images). Threats outside of Brunei due to widespread forest degradation and clearance.

Collections. One collection in the 1950's in Belait district. Of the ten sites across Borneo four are in protected forests where recent collections have been made.

Notes. New collections needed to confirm it is still present in Brunei.

Fig. 57. Map of P.decurrens collections showing EOO

Fig. 58. Map of collection locations of P,decurrens in Brunei

5. Palaquium gutta

Near Threatened (NT)

Reasons. P.gutta has been the most exploited species of Palaquium due to the high demand for its latex in the 19th century, when c. 88 million trees were felled (Wilkie, pers. comm). 371 known occurrences across its range, although many of these collectiona (especially from Peninsula Malaysia) are from late 1800's to early 1900's when demand for latex was at its

73 peak. Its range and frequency will have been severely depleted due to this historical widespread felling.

Range. Borneo, Sumatra and Peninsular Malaysia.

Habitat. Lowland mixed dipterocarp forest

Threats. Although not in protected forest, the Brunei occurrences are in apparently undisturbed forest (as seen from satellite map images) to the north of Ulu Temburong National Park. Threats most likely outside of Brunei where forest disturbance and clearance is widespread.

Collections in Brunei. Only known in Brunei from two collections in the 1950's both in Temburong district.

Notes. New collections are needed to confirm it is still present in Brunei. Its whole range should be assessed due to the historic widespread felling of this species.

Fig. 59. Map of P.gutta collections showing EOO

Fig. 60. Map of collection locations of P,gutta in Brunei

6. Palaquium herveyi

Near threatened (NT)

Reasons. AOO is low at 104 km², and only two occurrences are in protected forests. Across its range there has been widespread degradation and clearance of forests. No collections have been made in Borneo since 1960's.

Range. Borneo. and Peninsular Malaysia

Habitat. Lowland and hill mixed dipterocarp forest

Threats. There is no obvious threat to this species within Brunei as it is in protected forest of Ulu Temburong National Park. Threats are more likely outside of Brunei with only one other collection across its whole range in protected forest.

Collections in Brunei. Only known in Brunei from one collection from the 1950's in Temburong district.

Notes. New collections are needed for all of Borneo.

Fig. 61. Map of P.herveyi collections showing EOO

Fig. 62. Map of collection locations of P.herveyi in Brunei

7. Palaquium leiocarpum

Least concern (LC)

Reasons. In Brunei only two occurrences recorded. But taking the whole range of P.leiocarpum into account, it does not belong in a threatened category. It has a wide range across south-east Asia, with an EOO of 821,855.94 km². There are 164 known occurrences across its range, six in protected forests, with regular collections made in Borneo from 1950's to 1990's.

Range. Borneo and Penninsular Malaysia. (and possibly Sulawesi and Sumatra, mentioned in van Royen, 1960, and Chai & Yii, 2002)

Habitat. Swamp forest, mixed dipterocarp forest, kerangas forest.

Threats. There is no obvious threat to this species within Brunei as both collections are in protected forest, one at the southern point of Ulu Temburong National Park, the other in Labi Hills (Sungai Ingei Conservation) Forest Reserve in Belait district. Threats are more likely outside Brunei where there is widespread degradation and clearance of forests.

Collections in Brunei. Only known in Brunei from two collections, Belait district in 1950's and Temburong district 1990's.

Fig. 63. Map of P.leiocarpum collections showing EOO

Fig. 64. Map of collection locations of P.leiocarpum in Brunei

8. Palaquium majas

Endangered (EN)

EN B2ab(iii)

B2. AOO = 44 km², <500 km²; a. severely fragmented; b(iii). Continuing decline in area, extent and/or quality of habitat.

Range. Endemic to Borneo.

Habitat. Lowland mixed dipterocarp forest.

Threats. Though in a widespread habitat this species is only known from two records in Brunei, one is in protected forest of Labi Hills Forest Reserve, the other collected in 1896, in Brunei-Muara district which is now the most developed region of Brunei. The two locations are fragmented, at opposite sides of the country. Outside of Brunei only one other collection is within protected forest. A number of collections have been made in 1990's.

Collections in Brunei. Only known from two collections, 1896 in Brunei-Muara district and 1991 in Belait district.

Notes. Information is needed on whether a population still exits in the Brunei-Muara location.

Fig. 65. Map of P.majas collections showing EOO

Fig. 66. Map of collection locations of P.majas in Brunei

9. Palaquium microphyllum

Near threatened (NT)

Reasons. Fragmented distribution and low AOO of 148 km². Only three occurrences are in protected forests across its whole range. Degradation and forest clearance widespread across range and is found in peat swamp forest which is a seriously threatened habitat.

Range. Borneo and Peninsular Malaysia (and possibly Sumatra and Riouw, in van Royen, 1960).

Habitat. Lowland mixed dipterocarp forest, peat swamp forest.

Threats. In Brunei it is in unprotected forest in the developed and industrial Seria area.

Collections in Brunei. Only known in Brunei from one collection in 1957 in Belait district.

Notes. New collections are needed to confirm its presence in Brunei and Sumatra.

Fig. 67. Map of P.microphyllum collections showing EOO

Fig. 68. Map of collection locations of P.microphyllum in Brunei

10. Palaquium obtusifolium

Endangered (EN)

EN B2ab(iii)

B2. AOO = 64 km2, <500 km²; a. severely fragmented; b(iii). Continuing decline in area, extent or quality of habitat.

Range. Borneo and Sulawesi (and possibly Sumatra, Bali, the Phillipines and New Guinea, in van Royen, 1960).

Habitat. Mixed dipterocarp forest.

Threats in Brunei. Only known occurrence is in the Andalau Forest Resverve, although protected, the forest lies in a thin fragmented strip between the Seria by-pass and the coast. Threats outside of Brunei come from forest degradation and clearance.

Collections. Only two collections from Borneo, 1957 in Tutong district and 1982 in Central Kalimantan.

Notes. Andalau Forest Reserve was designated in 1940, making it one of the oldest protected forests in Brunei. New collections are needed to confirm its presence in Brunei and to assess its range within Borneo.

Fig. 69. Map of P.obtusifolium collections showing EOO

Fig. 70. Map of collection locations of P.obtusifolium in Brunei

11. Palaquium pseudocuneatum

Endangered (EN)

EN B2ab(iii)

B2. AOO = 56 km², <500 km²; a. severely fragmented; b(iii). Continuing decline in area, extent or quality of habitat.

Range. Endemic to Borneo.

Habitat. Freshwater swamp forest, peat swamp forest, lowland mixed dipterocarp forest, kerangas forest.

Threats in Brunei. In unprotected forest in Belait district, where one location appears degraded by sand mining (from satellite image). Across its whole range it occurs in two protected forests, both in Sarawak. Peat swamp is one of its habitats. This sensitive ecosystem has been disturbed in Brunei by industrial activity such as sand mining. May also be damaged by forest clearances in neighbouring Sarawak if on a connected area of peat dome.

Collections. Two collections in Belait district one in 1959 other unknown (van Niel 3814), a more recent collection was made in Sarawak in 2008.

Notes. New collections are needed to confirm its presence in Brunei.

Fig. 71. Map of P.pseudocuneatum collections showing EOO

Fig. 72. Map of collection locations of P.pseudocuneatum in Brunei

12. Palaquium pseudorostratum

Near threatened (NT)

Reasons. Low AOO of 124 km². Continuing decline in area, extent or quality of habitat, due to widespread disturbance and forest clearance across Borneo. Occurs in the threatened peat swamp habitat and fragmented kergangas forest.

Range. Borneo (and possibly the Philippines, in van Royen, 1960).

Habitat. Peat swamp forest, freshwater swamp forest, kerangas forest.

Threats. In Brunei it occurs in protected forest of Batu Apoi Forest Reserve, Temburong district. Threats are more likely ouside of Brunei from widespread forest degradation and clearance.

Collections. Only one collection in Brunei, Temburong district in 1959, for the rest of Borneo collections have been more numerous and range from 1950's to 2009.

Notes. New collections are needed to confirm it is still present in Brunei, collections are also needed to confirm it is present in the Philippines.

Fig. 73. Map of P.pseudorostratum collections showing EOO

Fig. 74. Map of collection locations of P.pseudorostratum in Brunei

13. Palaquium quercifolium

Vulnerable (VU)

VU B2ab(iii)

B2. AOO = 32 km², <2000 km²; a. ≤10 locations; b(iii). Continuing decline in area, extent or quality of habitat.

Range. Borneo, Sumatra and Sulawesi.

Habitat. Mixed dipterocarp forest.

Threats. Not threatened in Brunei where it grows in protected forest of Ulu Temburong National Park. Threats are more likely in the rest of Borneo, Sumatra and Sulawesi where forest disturbance and clearance are widespread.

Collections in Brunei. One collection from Temburong district in 1994.

Notes. 27 records of this species from only eight locations, 1 in Sulawesi, 1 in Sumatra, 1 in Brunei and four in the rest of Borneo.

Fig. 75. Map of P.quercifolium collections showing EOO

Fig. 76. Map of collection locations of P.quercifolium in Brunei

14. Palaquium ridleyi

Least concern (LC)

Reasons. In Brunei there are only two occurrences recorded. However P.ridleyii has a wide range across south-east Asia, with an EOO of 1 187 733.72 km² and over 50 known occurrences across its range. It does not belong in a threatened category. Regular collections between 1930's and 1990, from Borneo, Peninsula Malaysia and Sulawesi.

Range. Borneo, Peninsular Malaysia, Sulawesi (and possibly Sumatra, the Philippines, New Guinea and Indo-China, in van Royen, 1960 and Chai & Yii, 2002).

Habitat. Kerangas forest, peat swamp forest, mixed swamp forest.

Threats in Brunei. Both of the Brunei collections are in protected forest, one in Ulu Temburong National Park, the other in Berakas Forest Reserve.

Collections in Brunei. Only known in Brunei from two collections in the 1950's, in Brunei- Muara district and Temburong district.

Notes: Outside of Brunei it does not appear to occur in protected forest. Much of its distribution is in or close to coastal regions which are more likely to be developed than inland regions, and one of its known habitats is in the ecologically sensitive peat swamps. For these reasons, and due to the known forest degradation and clearance across south-east Asia, further records of occurrence in Brunei would be useful.

Reasons for the low representation in Brunei could be due to under collection, misidentification, or it could be locally abundant across its range and otherwise infrequent.

Fig. 77. Map of P.ridleyi collections showing EOO

Fig. 78. Map of collection locations of P.ridleyi in Brunei

15. Palaquium rioense

Critically Endangered (CR)

CR D

D. Restricted area of occupancy.

Only known from two montane locations; Mount Kinabalu in Sabah and Kong Kumul in Kalimantan. Only one record comes from Kalimantan in 1925. The seven Sabah species were collected between 1930's and 1970's.

Range. Borneo, (and possibly Riouw, in van Royen, 1960).

Habitat. Montane and hill forests, montane shale ridges.

Threats. A restricted area of just two locations makes it vulnerable to events that could wipe out the population. More data is need on the extent of the populations found at each site.

Collections in Brunei. No records found, but is in Hasan and Ashton's checklist (1964).

Notes. This species is restricted to montane habitats, if it does occurr in Brunei, the only likely location is in the vicinity of the highest peak, Bukit Pagon.

Fig. 79. Map of P.rioense collections showing EOO

Fig. 80. Map of collection locations of P.rioense in Brunei

16. Palaquium rivulare

Vulnerable (VU)

VU B2ab(iii)

B2. AOO = 36 km², <2000 km²; a. number of locations ≤10; b(iii). Continuing decline in area, extent and/or quality of habitat.

Range. Endemic to Borneo.

Habitat. Mixed dipterocarp forest, alluvial forest, and on limestone.

Threats. In unprotected forest in Brunei, with just one of its 19 occurrences across Borneo in protected forest. Threats are most likely in the rest of Borneo, as forests are being degraded or cleared.

Collections in Brunei. Only one known collection from 1959 in Temburong district, all collections from the rest of Borneo are from 1960's and 1970's.

Notes. New collections are needed to confirm it is still present in Brunei. This is a distinctive species, with the largest leaves of any Palaquium in Brunei, unlikely to be overlooked if encountered on collecting expeditions.

Fig. 81. Map of P.rivulare collections showing EOO

Fig. 82. Map of collection locations of P.rivulare in Brunei

17. Palaquium rostratum

Least concern (LC)

Reasons. It has a wide range across south-east Asia, with an EOO of 2 377 123.62 km². Over 400 known occurrences across its range, with regular collections made between 1901 and 2008, mainly from Peninsula Malaysia, Singapore and Sabah. Found in a range of forest types.

Range. Borneo, Java, Thailand, Peninsular Malaysia, the Philippines (and possibly Sumatra, Riouw and Sulawesi, in van Royen, 1960).

Habitat. Freshwater-swamp forest, mixed dipterocarp forest, kerangas forest.

Threats in Brunei. Two of its locations are in unprotected forest, of these one is in forest close to developed coastal land, the other in apparently undisturbed forest (as seen from satellite map images) to the north of the national park.

Collections. Known in Brunei by three collections from the 1950s', one in Belait district, and two in Temburong district.

Notes. New collections are needed to confirm it is still present in Brunei. Reasons for its low representation in Brunei could be due to under collection, misidentification, or it could be locally abundant across its range and otherwise infrequent.

Fig. 83. Map of P.rostratum collections showing EOO

Fig. 84. Map of collection locations of P.rostratum in Brunei.

18. Palaquium sericeum

Least concern (LC)

Reasons. Widespread across Borneo, found in a range of forest types. Although AOO is relatively low, Borneo (288 km²) and Brunei (28 km²), there are 266 known locations which are not severely fragmented. Of the eleven recorded locations in Brunei, five are in protected forests.

Range. Endemic to Borneo.

Habitat. Wide range of forests: lowland mixed dipterocarp forest, secondary forest, alluvial forest, and sometimes on limestone.

Threats. Not threatened due to wide range of habitats, and almost half occur in protected forests.

Collections.Regular collections made between the 1980's and 2003.

Fig. 85. Map of P.sericeum collections showing EOO

Fig. 86. Map of collection locations of P.sericeum in Brunei

19. Palaquium stipulare

Vulnerable (VU)

VU B2ab(iii)

B2. AOO = 32km², <2000 km²; a. number of locations ≤10; b(iii). Continuing decline in area, extent and/or quality of habitat.

Range. Endemic to Borneo.

Habitat. Lowland mixed dipterocarp forest, limestone hills.

Threats. In unprotected forest. One site appears to be close to sand mining activity (from satellite image). Outside of Brunei the widespread clearance of forest is a major threat.

Collections. Two collections from Belait district in 1957 and 1991. All collections from the rest of Borneo are from 1950’s to 1970’s.

Notes. There is a lack of recent collections from Sarawak, which has the most records for the species. Only one collection is from protected forest. New collections are needed to confirm it is still present in Sarawak. It is found in the widespread dipterocarp forest habitat, therefore expected to be found more frequently than current distribution data shows.

Fig. 87. Map of P.stipulare collections showing EOO

Fig. 88. Map of collection locations of P.stipulare in Brunei

20. Palaquium walsurifolium

Near Threatened (NT)

Reasons:

Low AOO of 52 km² and occurs in the seriously threatened peat swamp habitat.

Widespread forest clearance and degradation in neighbouring Sarawak.

No known occurrences are in protected forests.

Range: Borneo (and possibly Peninsular Malaysia and Sumatra, in van Royen, 1960).

Habitat: peat swamp forest, freshwater swamp forest.

Threats. Not in protected forest either in Brunei or in the rest of Borneo. Threats are most likely in the rest of Borneo, as forests are being degraded or cleared.

Collections. Only one known collection from 1957 in Temburong district, collections from the rest of Borneo date from 1951 with the most recent in 2009.

Notes. New collections are needed to confirm it is still present in Brunei. More location data is also needed to determine the extent and quality of its habitat and to confirm its range outside of Borneo. It is believed to have a wider range than in the PADME database which currently has no records for Sumatra or Peninsula Malaysia, both referred to by van Royen (1960).

Fig. 89. Map of collection locations of P.walsurifolium in Brunei

Fig. 90. Map of P.walsurifolium collections showing EOO

Chapter six

6. Discussion

6.1 Checklists A Checklist of the Flowering Plants and Gymnosperms of Brunei Darussalam (Coode et al, 1996) listed 19 species of Palaquium. This study has recorded a new record for Brunei, P.majas, thus the total number of species can be updated to 20. Another potential new record is P.beccarianum, but location information was vague and more evidence is needed to confirm this.

Of the 19 Brunei species in the 1996 checklist (Coode et al, 2006), eight had no specimens cited, stating only that they had been named in A Checklist of Brunei Trees (Hasan & Ashton, 1964). This publication also gave no cited material. A list of species growing in a region is an important record, but its usefulness increases when specimens are cited as it gives a point of reference for future researchers to confirm or contest the prescence of that species in Brunei. This study has for the first time cited specimens for seven of the uncited species: P.dasyphyllum, P.decurens, P.gutta, P.pseudorostratum, P.rivulare, P.stipulare and P.walsurifolium.

The only species with no specimens yet found for Brunei is P.rioense. This species has a restricted montane habitat type, and is the only species which is provisionally placed in the Critically Endangered (CR) IUCN category. If no specimens are found it could mean that the species has become extinct since being encountered by Hasan & Ashton in the 1960's, or perhaps that it had been misidentified.

This study has also identified some misidentified specimens in Coode et al's (1996) checklist. Ashton 34 (BRUN) was initially determined by van Royen as P.stipulare, but later cited in his revision of the genus (Royen, 1960) as P.quercifolium. In Coode et al (1996) this was cited as P.quercifolium. From the image seen, I agree with van Royen's initial determination of this specimen and confirm it is P.stipulare.

6.2 Taxonomic account This study has for the first time created a taxonomic account for the Palaquium of Brunei, giving full species descriptions for each of the 20 species. Limitations such as lack of material are apparent in some cases, and the descriptions should be added to as more material becomes available.

6.3 Palaquium morphology In the works of van Royen (1960) and Lam (1925) occasional variability is noted in the number of calyx lobes for Palaquium. In my opinion a calyx with two whorls of three lobes is a key character. Pennington (1991) uses this character as the first couplet in his key, and gives no mention of any variations. No variation in calyx number was seen for the 20 Brunei species.

Taxonomically informative morphological characters for the Palaquium of Brunei were found to be indumentum, leaf base, secondary veins, tertiary veins, and stamen number. Material for these characters was readily available to study during this research. However, other informative characters may have been overlooked due to lack of material such as fruit and seeds. It should be stressed that there is a significant difference between taxonomically informative characters and available characters (which may or may not prove to be informative).

For some species there is a complete lack of known material such as fruit and seed for P.rivulare, and seed for P.stipulare. An awareness of missing characters is useful so that they may be targeted during future collecting work in Brunei.

Uncertainty arises if characters are only sometimes mentioned on labels. For example some P.leiocarpum specimen labels record presence of stilt roots while others do not. This is either due to the collector forgetting to record the character, or that the character is not present. This issue can only be resolved with great knowledge of Palaquium species in the field and collectors noting absences (which is understandably problematic).

6.4 Collection data for conservation assessments Collection data gives the best currently known distribution of a species. As more data is inputted a species distribution will be better represented and this may impact on its conservation status. To take new data into account, conservation assessments should be reviewed every 5 or 10 years, as recommended by IUCN.

6.4.1 Limitations of collection data

Major collection data limitations identified in this study are due to varying collection densities (see below) and misidentifications. Another factor that initially affected distributions were cultivated records in the database, as collections from Singapore Botanic Garden gave unexpected distributions. In this study this error source was identified and omitted from distribution data.

6.4.2 Varying collecting densities Collection densities vary widely within the Malesian region. The tree flora of Brunei is considered relatively well collected compared to Kalimantan, Sumatra, Sulawesi and New Guinea, but less so in comparision to Sabah and Penninsula Malaysia (Johns, 1995). However the distribution maps produced in this study highlight the lack of collection data for many Palaquium species across their range, including Brunei.

Collection densities also vary within Brunei, with the highest collection densities in Belait district and Temburong district. Many collections for Temburong district are from Kuala Belalong where there is a field studies centre. This centre is a hugely important resource which focusses on the study of forest processes. However it potentially creates an abundance of collections within a small radius of the centre, leaving other areas of forest overlooked and suggesting this area is particularly species diverse.

To overcome this issue collection densities within Brunei should be monitored. This will identify poorly collected areas to target in future collecting work. An area of Brunei I suggest for future collections is the montane region of Bukit Pagon for which there are only two cited Palaquium specimens (of P.dasyphllyum and P.leiocarpum) and where P.rioense may be present.

6.4.3 Misidentification Misidentification of specimens affects species delimitation, distribution maps, and conservation assessments. In this study only the Brunei distributions can be considered accurate as each specimen has been verified by me. For the rest of the Palaquium species, inconsistencies in identifications are likely. Different determinations may be made by staff in different herbaria, although examples have been found where the same determiner identifies duplicate material as different species. The issue of misidentifications impacting conservation assessments highlights how fundamental the role of taxonomic experts are in conserving biodiversity.

6.5 Benefits and limitations of digital specimens

Digital images of specimens are an important resource allowing quick access to a greater number of specimens. However the quality of images varies. JSTOR (JSTOR, 2013) was useful for this study with high quality images of many type specimens and a useful tool to make accurate measurements. Some herbaria provide limited online images of their

97 collections (E, K, L). The use of them varies, with Leiden focussing on label images. Images on the Sapotaceae Resource Centre are not such high quality as JSTOR, but it holds a far greater number of Sapotaceae images making it a major resource.

For distinctive species such as P.rivulare, with the longest leaves of any Brunei Palaquium, images are very useful as this diagnostic vegetative character is easily recognised. But for species which cannot be clearly identified vegetatively, the resource is less useful. For example P.herveyi and P.walsurifolium can vegetatively be best distinguished by the presence (P.herveyi) or absence (P.walsurifolium) of sparse hairs on the lower leaf surface. It is not possible to see such fine character detail on images.

A suggestion to greatly improve the digital image resource is to link microscope images of dissected flowers to specimens. Such access to floral characters would have been extremely useful in this study to distinguish otherwise similar species such as P.pseudorostratum and P.pseudocuneatum. Floral imaging of specimens would be expensive and time consuming, but would lead to a resource of far greater use.

It was not possible to identify a number of digital images from BRUN, where vegetative characters alone were inconclusive. This underlines the importance of access to actual herbarium material (especially the fertile material) for taxonomic study and accurate identifications.

6.6 Future work A greater understanding of Palaquium in Brunei has been gained in this study through reviewing Palaquium taxonomy and assessing its conservation status. To put this study into context the other five genera of Sapotaceae in Brunei should be treated in the same way in future work, and should then be expanded to cover the Sapotaceae of the whole of Borneo, a natural floristic region.

6.7 Conclusion Palaquium is an important component of Brunei forests, it grows in every major forest type except mangrove forests. There are no endemic species found in Brunei, however there is a risk of species becoming anthropogenic endemics in Brunei as forests continue to be felled across Borneo. In this event, a greater proportion of Brunei’s forests should be designated as protected conservation forest.

Species concepts are relatively stable for the Palaquium of Brunei, however a lack of morphological data remains a limiting factor for the study of some species. Future molecular work would be useful to confirm the splitting of morphologically similar species such as P.pseudocuneatum and P.pseudorostratum.

A major recent resource for taxonomy is the availability of digital specimens. While useful to a point, they can not be relied on soley for use in revisions, and whenever possible herbarium specimens should be viewed.

This study highlights the importance of clean distribution data. The process of gathering such data begins with recording precise collection locations in the field, and continues with taxonomic work in herbaria. If these two steps are carried out to a high standard the data available for use in conservation assessments will be of greater significance.

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Appendix. Representative specimen images for the 20 Palaquium species of Brunei

1. P.calophyllum 2. P.cochleariifolium

3. P.dasyphyllum 4. P.decurrens

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5. P.gutta 6. P.herveyi

7. P.leiocarpum 8. P.majas

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9. P.microphllum 10. P.obtusifolium

11. P.pseudocuneatum 12. P.pseudorostratum

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13. P.quercifolium 14. P.ridleyi

15. P.rioense 16. P.rivulare

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17. P.rostratum 18. P.sericeum

19. P.stipulare 20. P.walsurifolium

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