Bucephalandra oncophora S. Y. Wong & P. C. Boyce

Small obligate rheophytic herbs to 14 cm tall. Stem erect, in older plants creeping and rooting with active portion sub-erect. Leaves to c. 8 together, spreading; petiole 3.5 - 4 cm long × c. 2 mm in diam., adaxially canaliculate, scabrid, reddish, sheathing at extreme base, wings extended into a very narrowly triangular ligular portion to 1.5 cm long; blade elliptic, 9 - 11 cm long × 2.5 - 3 cm wide, coriaceous, semi-glossy dark green adaxially, paler yellowish reddish green abaxially, base cuneate, apex rounded and apiculate for c. 5 mm, margin undulate; midrib abaxially and adaxially prominent, strongly reddish abaxially; primary lateral veins 3 or 4 on each side, diverging at c. 35° and running to a marginal vein; interprimary veins finer; secondary venation adaxially ± obscure, abaxially faint; tertiary venation adaxially obscure, forming a faint tessellate reticulum. Inflorescence solitary; peduncle exceeding petioles, 8 - 12 cm long × 3 mm in diam., longitudinally sulcate, medium green with ridges dark red. Spathe oblong-ovate, not constricted, 6 - 7.5  cm long; lower spathe narrowly funnel-form, green, persistent; limb gaping, then caducous, creamy white, apiculate for c. 4 mm, apiculum green. Spadix 4 - 4.5 cm long; pistillate zone 4 - 7 mm long × 3 - 4 mm in diam., with 3 or 4 spirals of pistils; pistils polygonal-globose, often radially 3- or 4-sulcate, c. 0.5 mm in diam., lime-green; stigma stipitate, capitate, c. ½ diameter of ovary, producing a large stigmatic droplet at pistillate anthesis; pistillodes 2 - 4 at base of pistillate zone, arcuate cylindrical and much-exceeding pistils, c. 3 mm long, cream; interstice with c. 2 rows of scale-like staminodes, these c. 2 mm long × c. 2.3 mm wide, margins recurved, initially erect, then spreading, initially white, later (post-anthesis) becoming green and persisting to cover developing fruit; staminate zone 1 - 1.5 mm long × 5 - 7 mm in diam., weakly conic, consisting of 6 or 7 rows of flowers; staminate flowers greenish; stamen comparatively large, c. 1 mm across; filament short, stout; connective inverted spathulate; thecae inserted ventrally, globose-ellipsoid, c. 1 mm long × c. 0.5 mm wide, smooth; thecae horns very short, c. 0.2 mm long, spreading; appendix bluntly cylindrical, somewhat constricted ¼ - ? from base with area below constriction noticeably wider than remainder of appendix, 2 - 2.5 cm long × 5 - 7 mm in diam., greenish cream; appendix staminodes dimorphic, those of basal 1/4-1/3 of spadix rounded and umbonate, with a ventral suture (resembling inflated staminate flowers), c. 2 mm in diam., those of remainder of spadix irregularly polygonal, truncate or nearly so, lower few with a suture, remainder not, 0.5 - 1 mm in diam. Infructescence not known.