The Taxonomy and Conservation of Palaquium in Brunei
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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 ii 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. iii 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. iv 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 vii 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