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

Small but robust obligate rheophytic herbs 6 - 14  cm tall, sometimes forming patches up to 50 cm across. Stem creeping and rooting with active portions erect, branching repeatedly, branches up to 10 cm long × c. 1.5 cm in diam. Leaves many together; petiole 6 - 8 cm long × c. 1.5 mm in diam., adaxially canaliculate, bright reddish purple, sheathing at extreme base, wings extended into a very narrowly triangular ligular portion to 3 cm long; blade elliptic to lanceolate 6 - 9 cm long × 2.3 - 3 cm wide, rather thickly coriaceous, weakly glossy dark blue-green with major veins paler adaxially, paler and reddish abaxially, base cuneate, apex rounded and apiculate for c. 4 mm, margin markedly undulate; midrib abaxially and adaxially prominent, strongly reddish abaxially; primary lateral veins c. 5 on each side, diverging at 25° - 60° and running to a marginal vein; interprimary veins much finer; secondary venation adaxially ± obscure, abaxially fine. Inflorescence solitary, occasionally two together separated by a foliage leaf; peduncle exceeding petioles, 4 - 5 cm long, conspicuously longitudinally sulcate and occasionally distally winged, reddish purple, this colour derived from dense tiny speckles. Spathe broadly ovate, not constricted, 2.5 - 3  cm long; lower spathe funnel-form, lime-green, insertion on peduncle reddish purple, persistent; limb inflating and gaping distally to form a narrow opening at pistillate anthesis, caducous during staminate anthesis, glistening white, apiculate for c. 3 mm, apiculum green. Spadix c. 1.5 cm long, very shortly stipitate; stipe less than 0.3 mm long, light green; pistillate zone c. 3 mm long × c. 3 mm in diam., with c. 3 spirals of pistils; pistils slightly densely arranged, cylindric-globose, c. 2 mm long × c. 0.5 mm in diam., bright lime-green; stigma sessile, rather discoid umbonate, c. ½ diameter of ovary, papillate at anthesis; pistillodes in a single incomplete row at base of pistillate zone, squat fusiform with a short terminal beak, in all c. 0.2 mm in diam., glossy white; interstice with 2 rows of scale-like staminodes, these c. 2 mm long × c. 1 mm wide, ventrally slightly umbonate, staminodes initially erect (pistillate anthesis), during staminate anthesis reflexing until almost downturned with staminode beyond mid-part ascending, initially white with narrowed base green, later (post-anthesis) becoming green and persisting to cover developing fruit; staminate zone 4 - 6 mm long × 4 - 5 mm in diam., consisting of 4 or 5 rows of flowers; staminate flowers creamy yellow; stamen comparatively large, c. 1.5 mm across; filament short but clearly defined; connective cap-like and dorsally arched, pale yellow; thecae inserted ventrally on connective, with appearance of being suspended from it, paler than connective, individually ellipsoid, c. 1 mm long × c. 0.4 mm wide, smooth; thecae horns c. 1/4 length of associated theca, ascending, stiffly setaceous; appendix bullet-shaped to globose, 4 - 5 mm long × 3 - 4 mm in diam., bright yellow; appendix staminodes mostly squat cylindrical, 0.5 - 1 mm in diam., tops brain-like, densely arranged, lowermost ones transitioning to staminate flowers in appearance. Fruiting spathe broadly funnel-form, c. 1 cm in diam., medium green, with green shield-shaped staminodes persistent and spent distal part of spadix falling; berry depressed globose, 1 - 1.8 mm long × 1 - 1.5 mm in diam., medium green, with numerous seeds, berries forming a hemispherical cluster protected by persistent staminodes, later pushed off and falling to reveal mature fruits; fruits decomposing at maturity, forming a pulp with seeds held in persistent lower spathe; seed not seen.