Ooia grabowskii (Engl.) S.Y.Wong & P.C.Boyce

Rheophytic herb 20-50 cm tall. Stem c. 4-8 (-20) cm long, mostly condensed, occasionally more elongate with internodes to 1 cm long, 0.6-1.5 cm diam., roots strong, 2.5-4 mm thick. Leaves c. 4-8 together; petiole green to purple, 6-23 cm long, 2.5-3 mm diam., adaxially canaliculate, sheathing only at the very bottom of the base, the wings extended into a narrowly triangular ligular portion 5-10 cm long; blade narrowly elliptic to elliptic-oblong, 12-28 cm long × 4-10 cm wide, dull mid- to dark green adaxially, very rarely variegated in an irregular spattered pattern, abaxially paler, the base cuneate, the apex acute and apiculate for 2-3 mm; midrib prominent abaxially, adaxially somewhat impressed, sometimes abaxially purple, with 8-14 (-20) primary lateral veins on each side, more or less regularly alternating with lesser interprimaries and diverging at c. 45-60^o; secondary venation abaxially fine, adaxially obscure; tertiary venation obscure. Inflorescence solitary (sometimes a few together but alternating with foliage leaves); peduncle 10-22 cm long, 2-3 mm diam., always shorter than the leaves, green to purple. Spathe ovoid-subcylindric, (2-) 3-5 cm long, 0.8-1.4 cm diam., apically beaked for 2.5-4 mm, persistent, rose pink to purple to brownish pink, more or less nodding at anthesis. Spadix (1.2-) 2.2-3 cm long, subcylindric to slightly clavate, shortly stipitate with the stipe adnate to the spathe, white to yellowish; female flower zone (0.3-) 0.5-1 cm long, 0.3-0.9 cm diam.; ovary ovoid, slightly angled, c. 1.4 mm diam.; stigma sessile to raised on a short style to 0.5 mm long, discoid, about as wide as the ovary, drying almost black; interpistillar staminodes absent from among the pistils, confined to a robust zone below the female flower zone of up to 6 oblique whorls; staminodes shortly stipitate, to 1.2 mm diam., irregularly polygonal, flat-topped with the centre usually somewhat impressed and the margins pale coloured (? with dried exudate); sterile interstice absent; male flower zone cylindric to ellipsoid, apically obtuse, fertile to apex; stamens crowded, mostly arranged in pairs, truncate, flat-topped, more or less rectangular from above, c. 1.1 mm across, minutely hairy on the upper surface especially at the margins; thecae opening through apical pores. Fruiting spathe ovoid-subcylindric, green to reddish green to greenish brown, obliquely erect, to 5 cm long, persistent then eventually more or less disintegrating; fruits in a dense cluster; berry broadly obovoid, crowded with old stigma remnant, 2-2.5 mm long, 2.8-3.2 mm diam.; seed subcylindric, 2.4-2.6 mm long, slightly ribbed, light brown with a transparent long curved micropylar appendage.