Arisaema pachystachyum Hett. & Gusman

Seasonally dormant herb. Tuber de-pressed globose, to ca. 6 cm in diam., ca. 4 cm high, producing a few annual, depressed globose offsets. Shoots either unifoliate (smaller specimens) or bifoliate (larger specimens) and then with a pseudostem. Largest cataphyll greyish green chequered extensively dark pink. Petiole 27-45 X 1-1.5 cm, lower 5-20 cm sheathing and forming a pseudostem with the peduncle, smooth, pale green; lamina trisect, to 70 cm in diam; leaflets elliptic or obovate, 18-35 cm long, 9-18 cm wide, top short aristate, median leaflet long petiolulate (to 4 cm long), lateral leaflets shorter petiolulate (to ca. 1.5 cm). Peduncle sturdy, shorter than petiole, 16-24 cm long (from tuber to top), 0.5-1.5 cm in diam., as petiole; spathe 9-16 cm long, 4-5 cm in diam. (base), lower 2.5-6 cm convolute, 1-2 cm in diam., tubular, slightly tapering to the top, outside and inside white but ventral side flushed with green or with faint green stripes near the base, limb hooded, 4.5-6 cm long, 2-4 cm in diam., triangular or elongate triangular, acute or drawn out in a long acuminate tip, veins thickened, outside and inside green. Male spadix shorter than spathe, 5-6 cm long; male zone conical, with distinct swollen axis, 1.5-2 cm long, 0.4-0.6 cm in diam. at the base, 0.2-0.3 mm at the top, flowers distant, upper part of male zone with few staminodes; appendix very thin, 1 mm in diam., gradually tapering to the acute top, pale olive green, basal part erect, then curved downwards. Female spadix 6.5 cm long, sessile; female part elongate conical, 1.3-2.5 cm long, 1-1.2 cm in diam. at the base, 0.5 cm in diam. at the top; appendix elongate, 5-6 cm long, basal part slightly thickened and with regularly arranged but distant staminodes, remainder smooth, filamentous, 1-2 mm in diam., dull olive green, top curved forward and sometimes downward, acute. Ovaries elongate, truncated, 3 mm long, 2 mm in diam., unilocular, 5-7-ovulate, glossy dark green with whitish striations; style short but distinct, to 0.2-0.5 mm long, conical, glossy dark green; stigma depressed or subhemispheric, slightly broader than style, pencillate, white. Male flowers consisting of 2-3 stamens; stamens 1-2 mm long; filaments basally or entirely connate and branching at the top, 0.5-1 mm long, white; anthers elliptic, ca. 0.8 mm long, white, the top dark purple, opening apically with oval pores; pollen pale blue. Staminodes aristate, thin, 0.5-5 mm long, 0.1-0.8 mm in diam., dirty greenish with purple spots and flushes or upper part purple, top obtuse.