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

Small obligate rheophytic herbs to 16 cm tall. Stem erect, in older plants creeping and rooting with active portion sub-erect. Leaves to c. 8 together, spreading; petiole 6 - 8 cm long × c. 2 mm in diam., adaxially canaliculate, scabrid, red, sheathing at extreme base, wings extended into a very narrowly triangular ligular portion to 3 cm long; blade elliptic to oblong lanceolate, 9 - 10.5 cm long × c. 2 cm wide, slightly coriaceous, semi-glossy dark green adaxially, paler yellowish 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 c. 4 on each side, diverging at c. 55° 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, 7 - 13 cm long × c. 2 mm in diam., longitudinally sulcate, medium green with ridges dark, often somewhat winged near junction with spathe. Spathe oblong-ovate, not constricted, 4 - 5 cm long; lower spathe narrowly funnel-form, green, persistent; limb gaping to form a longitudinal slit at pistillate anthesis, opening almost flat and tearing from persistent lower spathe at staminate anthesis, then tearing into irregular strips and pieces before falling, then caducous, ivory, apiculate for c. 4 mm, apiculum green. Spadix 3 - 4 cm long; pistillate zone 4 - 7 mm long × 3 - 4 mm in diam., with 3 or 4 spirals of pistils; pistils polygonal-globose, c. 0.5 mm in diam., lime-green; stigma stipitate, capitate, c. ½ diameter of ovary, producing a large stigmatic droplet at staminate anthesis; pistillodes 2 - 4 at base of pistillate zone, spathulate, equalling pistils, c. 1.5 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, green; staminate zone 7 - 10 mm long × 4 - 7 mm in diam., weakly conic, consisting of 4 or 5 rows of flowers; staminate flowers rather distant, greenish; stamen comparatively large, c. 1 mm across; filament short, stout; connective arching, strap-like, tip thickened, pale green; thecae inserted ventrally, globose-ellipsoid, c. 1 mm long × c. 0.4 mm wide, smooth; thecae horns very short, c. 0.2 mm, spreading; appendix bluntly cylindrical, somewhat constricted 1/4 - 1/3 from base, 2 - 2.5 cm × 5 - 7 mm in diam., greenish cream; appendix staminodes dimorphic, those of basal 1/4 - 1/3 of spadix rounded polygonal, 2 - 2.5 mm in diam., with a central tiny hole, those of remainder of spadix irregularly polygonal, truncate or nearly so, 0.5 - 1 mm in diam. Fruiting spathe funnel-form, c. 1.5 cm in diam.; fruits and seeds not seen.