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

Diminutive obligate rheophytic herbs c. 2 cm tall, occurring in extensive patches. Stem creeping with active portion sub-erect, branching repeatedly, c. 1 - 2.5 mm in diam. Leaves appressed to ground, scattered along stems and forming small clusters at shoot tips; petiole 0.5 - 1 cm long × c. 2 mm in diam., adaxially canaliculate, greenish brown, sheathing at extreme base, wings extended into a very narrowly triangular ligular portion to 1  cm long; blade obovate, 3 - 5 cm long × 1 - 1.5 cm wide, thinly coriaceous, metallic bluish olive-green adaxially, paler and reddish abaxially, base cuneate to sub-decurrent, apex rounded and apiculate for c. 1 mm, margin usually weakly undulate; midrib adaxially somewhat prominent, abaxially much finer, although reddish and therefore conspicuous; primary lateral and interprimary veins very fine and not differentiated, c. 10 veins per side; secondary venation abaxially very fine and forming faint reticulum. Inflorescence solitary; peduncle slender, exceeding petioles, c. 3 cm long × c. 1.5 mm in diam., conspicuously longitudinally sulcate and distally winged, pale brownish with reddish ridges. Spathe broadly ovate, not constricted, c.  1.5  cm long; lower spathe widely funnel-form, very pale pinkish green, persistent; limb inflating, then gaping, then caducous, white, apiculate for c. 2 mm. Spadix 5 - 8 mm long; pistillate zone c. 1 mm long × c. 3 mm in diam., with 1 spiral of pistils; pistils compressed globose, c. 0.5 mm in diam., yellow-green; stigma sessile, umbonate, c. ½ diameter of ovary, papillate and with a conspicuous stigmatic droplet at anthesis; pistillodes absent; interstice with c. 2 rows of scale-like staminodes, these c. 1.5 mm long × c. 0.8 mm wide, very shallowly concave, very pale pink with darker pink minute speckles; staminate zone 2 - 3 mm long × c. 2.5 mm in diam., consisting of c. 3 irregular rows of flowers; staminate flowers brownish pink; stamen large, c. 1 mm across, brownish pink; filament very short; connective triangular-prismatic; thecae inserted ventrally, ellipsoid, c. 1 mm long × c. 0.3 mm wide, smooth; thecae horns longer than remainder of stamen, setaceous, upward curving; appendix globose to bluntly cylindrical, 1 - 2 mm long × 1.5 - 2 mm in diam., pinkish cream; appendix staminodes very few, fused, truncate, 0.5 - 1 mm in diam., upper surface smooth and glossy. Fruiting spathe widely and shallowly funnel-form, c.  1  cm in diam.; fruits and seeds not seen.