Homalomena vietnamensis Bogner & V.D.Nguyen

Plant herbaceous, adult specimens 50-60 high. Stem erect, 20-30 cm high and 1.8-2 cm in diam., only old long stems decumbent, old stems covered with dry, brown leaf remnants; internodes short (c. 0.5 cm long); roots 2-3 mm in diam., branched (second order roots much thinner); upper stem portion with several subhorizontally spread leaves. Petioles 25-35 cm long, near base 0.7 cm and near apex 0.5 cm in diam., mid green, most of its length terete, distally on upper side slightly flattened at a length of 3-5 cm, non-geniculate. Leaf sheath 13-18 cm long and well developed, persistent (as long as the leaf is alive) and in the middle 1-2 cm broad, apex of sheath acute. Leaf blade broadly ovate, 17-20 cm long and 13-18 cm wide (nearly as broad as long) [only juvenile leaves somewhat narrower and with an obtuse base], base (of adult leaves) always truncate to obtuse (never cordate!), apex cuspidate with a (3-)4-5 mm long mucro, blade above dark green and glossy, underneath more or less light green and not glossy; venation parallel-pinnate, 6-7(-8) primary lateral veins on each side of the strong mid vein and with a distance of 1-2 cm from each other, sunken above and prominent underneath, second order veins thinner and parallel between the primary ones, third order veins much thinner and very close to each other. Cataphylls 8-15 cm long, light green with reddish tinge. Inflorescences shorter than petioles, 1-3 in a sympodium. Peduncle 12-14 cm long and 0.4-0.5 cm in diam., terete and somewhat thicker below spathe, ± greenish and reddish tinged, peduncle first erect, after anthesis bent (and turned downwards). Spathe (6.5-)7-8 cm long and c. 2 cm in diam. in the middle, non-constricted, thick, ending in a 3-4 mm long mucro, dark green outside and very light green to whitish inside, convolute and closed after anthesis. Spadix 3-3.5 cm long, cylindric (only nearly half the length of the spathe), with a stipe c. 2 mm long and 4 mm in diam., greenish white; female zone 1.3-1.5 cm long and 0.7 cm in diam.; male zone 1.5-1.8 cm long and c. 0.7 cm in diam., slightly ellipsoid, cream-coloured, apex blunt, fertile to the apex. Flowers unisexual, naked. Female flowers densely arranged; gynoecium ovoid, c. 2 mm tall, with one much shorter staminode each; ovary 1.1-1.2 mm in diam., greenish white, usually with 3 parietal placentae, ovules hemianatropous, many; style attenuate, 0.5-0.6 mm long, of the same colour as the ovary; stigma discoid, 0.6-0.7 mm in diam., ± as broad as style, whitish brown; staminode slender, subcylindric to slightly clavate, 1-1.1(-1.2) mm long, whitish. Male flowers consisting of usually (2-)3-4 free stamens, often somewhat irregularly arranged; stamen truncate, c. 1 mm tall, subrectangular in view from above, c. 1 mm long and 0.7-0.8 mm wide; between female and male flowers two rows of single stamens or staminodes (some very similar to stamens but lacking thecae); pollen grains inaperturate, ellipsoid, 20-22 μm long and 15-17 μm wide, exine smooth (psilate).