Wong and Boyce, 2016 Studies on Schismatoglottideae () of Borneo LVII: ... Studies on Schismatoglottideae (Araceae) of Borneo LVII: Bucephalandra filiformis – a new species from Maligan, Sarawak, Malaysian Borneo

Wong Sin Yeng* Department of Science & Environmental Ecology Faculty of Resource Science & Technology Universiti Malaysia Sarawak 94300 Kota Samarahan Sarawak, Malaysia [email protected]

Associate Researcher Harvard University Herbaria 22 Divinity Avenue Cambridge, MA 02138 USA *corresponding author

Peter C. Boyce Honorary Research Scientist Ludwig-Maximilians-Universität München Department Biologie I Systematische Botanik und Mykologie Menzinger Straße 67, 80638 München Germany [email protected]

ABSTRACT most recent identification key to Bucephalandra filiformis is described as a Bucephalandra species. new species with uniquely stiff linear leaf blades, illustrated from living from KEY WORDS the Maligan Range (Sarawak & Sabah, Malaysian Borneo), and inserted into the Rheophytes, sandstone, upper hill forest.

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INTRODUCTION Air Terjun Payeh Maga, below Camp 2, 04° Fieldwork in the Maligan Range (straddling 26’ 15.1”N 115° 31’ 27.9”E, 9 Sep 2014, P. the border of Sarawak & Sabah, Malaysian C. Boyce et al. AR-4915 (holotype SAR – Borneo) resulted in collection of several alcohol!; isotype: M – alcohol!). Figure 1. puzzling rheophytic aroid species. One of these has now flowered in cultivation and Diagnosis proven to be a previously undiscovered species of Bucephalandra, unique in the Bucephalandra filiformis is immediately by the stiff linear leaf blades. It is here distinguished from all other species of the described as Bucephalandra filiformis S. Y. genus Bucephalandra by the stiff linear leaf Wong & P. C. Boyce, sp. nov. Recognition blades. of this novelty takes Bucephalandra to 30 described species. Description Dimensions in the descriptions are derived Small solitary obligate rheophytic herbs from fertile (i.e., mature) plants. Seedlings to c. 8 cm tall. Stem initially erect, later have overall smaller measurements. shortly creeping and rooting with active portion sub-erect, c. 5 mm in diam.. Leaves Geological occurrences recorded in this up to c. 15 together, spreading to sub-erect; paper are verified by the excellent geological petiole 1–2 cm long × c. 2 mm in diam., map of Tate (2001). dorsally narrowly and shallowly canaliculate, ventrally longitudinally ribbed, reddish brown, sheathing at extreme base, wings Bucephalandra filiformis may be inserted in the extended into a very narrowly triangular key to Bucephalandra species presented in ligular portion 2–3.5 cm long, light red to Wong & Boyce (2014a) as follows: brownish; blade linear, 7 – 11 cm long × 4 – 6 mm wide, stiff, semi-matte deep olive 2. Appendix verrucate or brain- green adaxially, much paler greenish white like ...... 3 with the blade margin finely deep green, – Appendix staminodes smooth ..... 7 (“6”) base cuneate, apex acute (narrow leaf 3. Leaf blades linear, stiff . . blades) to aristate (wider leaf blades), . . . Bucephalandra filiformis apiculate for 2 – 3 mm; midrib abaxially – Leaf blades never linear, usually not stiff; and adaxially prominent, adaxially if stiff then never linear concolorous with blade, abaxially dull red; 4, etc., = 5, etc., in Wong & Boyce (2014a). primary lateral veins two, arising from leaf blade base and running along the margin; Bucephalandra filiformis S. Y. Wong & P. interprimary veins hardly differentiated, C. Boyce, sp. nov. Type: Malaysian Borneo, together totalling c. 15 per side, diverging at Sarawak, Limbang, Lawas, Maligan Range, c. 30° and running to a marginal vein;

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Figure 1. Bucephalandra filiformis S. Y. Wong & P. C. Boyce A. & B. Plants in habitat on moss-covered sandstone boulders. C. Habitat. D. at pistillate anthesis. E. Spadix at pistillate anthesis, nearside portion of spathe artificially removed, note that scale-like staminodes of interstice, and staminate flowers, are still erect. F. Detail of spadix at staminate anthesis; that the staminate flowers have reflexed and changed to salmon-pink, and that the interstice staminodes have reflexed note, too, that stigmas have darkened and are no longer receptive. A–H from AR–4186. Images © P.C. Boyce.

Aroideana VOL 39 NO 2, 2016 58 Wong and Boyce, 2016 Studies on Schismatoglottideae (Araceae) of Borneo LVII: ... secondary and tertiary venation ± mm wide, smooth; thecae horns c. 1/5 obscure. Inflorescence solitary; peduncle length of associated theca, setaceous, exceeding petioles, 4–7 cm long × c. 1.5 outward-pointing; appendix ellipsoid, 1 – mm in diam., somewhat longitudinally 1.5 cm long × c. 5 mm in diam., cream; ridged, reddish. Spathe slender-fusiform, appendix staminodes obpyramidal, tops not constricted, c. 3 cm long; lower spathe irregularly polygonal, lower ones well- obliquely funnel-form, green, persistent; defined, terminal ones coalesced, truncate, limb gaping at pistillate anthesis, then 0.5–1 mm in diam., weakly verrucate and caducous, white shading to green at junction somewhat glossy, cream. Infructescences with lower persistent spathe, limb acuminate not seen. for c. 1 cm and apiculate for c. 4 mm, apiculum green. Spadix 2 – 2.5 cm long; Ecology — Rheophytic on semi-shaded pistillate zone c. 5 mm long × c. 1.5 mm in mossy sandstone boulders in wet upper hill diam., with c. 2 spirals of pistils; pistils forest at about 850 m asl. weakly rhombic-globose, c. 0.5 mm in diam., bright green; stigma sessile, Distribution — Bucephalandra filiformis is umbonate, c. ½ diameter of ovary, known only from the Maligan Range. producing a conspicuous meniscus-like droplet at anthesis, later (post-anthesis) Etymology — From the Latin feminine sunken centrally; pistillodes 2–4 at base of adjective filiformis, threadlike, denoting the pistillate zone, compressed clavate, c. 0.5 form of the leaf blades. mm long and wide, waxy white; interstice with 2 rows of scale-like staminodes, these c. 2 mm long . 1.5 mm wide, ventrally Notes — The stiff very narrow leaf blades gibbose, margin spathulate, creamy white, of Bucephalandra filiformis have no equal in erect during pistillate anthesis, reflexing the genus Bucephalandra although similar leaf prior to staminate anthesis; staminate zone blades occur in Fenestratarum culum P. C. c. 5 mm long × c. 4 mm in diam., consisting Boyce & S. Y. Wong, Aridarum montanum of c. 3 rows of flowers; staminate flowers Ridl., and in some forms of the highly during pistillate anthesis ascending to polymorphic (and likely polyphyletic) A. display almost entire ventral surface, caulescens M. Hotta. All are obligate reflexing during staminate anthesis to rheophytes. present ventral surface lowermost, creamy yellow ageing during staminate anthesis to Observations of flowering plants revealed salmon-pink, thecae paler and somewhat that the staminate flowers change colour translucent; comparatively large, c. from creamy white to salmon-pink as 2 mm long; filament small, stout; anthesis progresses from pistillate (when the connective strap-shaped; thecae inserted staminate flowers are erect with the ventral ventrally, ellipsoid, c. 1 mm long × c. 0.5 surface exposed) to staminate (staminate

Aroideana VOL 39 NO 2, 2016 59 Wong and Boyce, 2016 Studies on Schismatoglottideae (Araceae) of Borneo LVII: ... flowers refkexing reflexing to place ventral Wong S. Y. & P. C. Boyce. 2013. The role of surface lowermost). These movements are the interstice staminodes of emulated by the scale-like staminodes of the Bucephalandra Schott (Araceae: interstice. See Wong & Boyce (2013) for a Schismatoglottideae). Newslett. Int. summary of the role of the interstice Aroid Soc. 35(2): 11–12. staminodes in Bucephalandra. Wong S. Y. & P. C. Boyce. 2014a. Studies on In general Bucephalandra species are plants Schismatoglottideae (Araceae) of of low elevations, with rather few of the 30 Borneo XXX – New species and recognized species occurring about 400 m combinations for Bucephalandra. asl and only three other species occurring at Willdenowia 44: 149–199. altitudes higher than that of B. filiformis: Bucephalandra kishii S. Y. Wong & P. C. Wong S. Y. & P. C. Boyce. 2014b. Studies on Boyce, B. magnifolia H. Okada & Y. Mori, Schismatoglottideae (Araceae) of Borneo and B. tetana S. Y. Wong & P. C. Boyce XXXXI: Additional new species of (Wong & Boyce 2014a). Bucephalandra. Willdenowia 44: 415– 421. Other material examined (Paratype): MALAYSIAN BORNEO: Sarawak: Limbang, Lawas, Maligan Range, Air Terjun ACKNOWLEDGEMENTS Payeh Maga, below Camp 2, 04° 26’ 15.1”N 115° 31’ 27.9”E, 9 Sep 2014, P. C. Boyce et al. This is part of an on-going research AR-4916 (SAR – alcohol!; M – alcohol!). project funded by the Ministry of Higher Education, Malaysia by the Exploratory Research Grant Scheme Vote No. REFERENCES NRGS/1089/2013-(03). Fieldwork was most recently under Sarawak Forestry Tate R. B. 2001. The geology of Borneo island Department Permission to Conduct CDROM. – Kuala Lumpur: Persatuan Research on Biological Resources - Permit Geologi Malaysia / Geological No. NCCD.907, 4.4(JLD.12)-51 and Park Society of Malaysia. Permit No 121/2015. The collaboration and support of the Sarawak Forestry Department and the Sarawak Biodiversity Centre are gratefully acknowledged.

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