勐腊芋 meng la yu

Herbs, terrestrial, stoloniferous. Rhizome 20-40 × 3-7 cm; stolons 6-10 per plant, pale green, trailing horizontally, simple, 15-20 cm × ca. 4 mm; internodes cylindric, ca. 4 cm, without tubercles. Leaves 5 or 6 together; petiole pale greenish, cylindric, ca. 50 × 1 cm, pubescent, proximal half sheathing; leaf blade pale green abaxially, glossy green adaxially, peltate, ovate-cordate, ca. 40 × 25 cm, membranous, pilose; primary lateral veins 7-9 pairs, sharply raised abaxially; marginal vein 1-3 mm from margin, inconspicuous. Inflorescences (2 or)3(or 4); peduncle pale green, cylindric, shorter than petioles, ca. 20 cm, pubescent. Spathe greenish, constricted between proximal tubular part and limb, proximal part nearly fusiform, 3-6 × ca. 1.2 cm; limb basally open, apically convolute, erect, not reflexed, yellowish, oblong-lanceolate, 13-18 × 4-6 cm. Spadix sessile, shorter than spathe; female zone green, cylindric, ca. 2 × 1 cm, separated from male zone by a narrower zone of synandrodes; ovary ovoid to oblong, ca. 1.5 mm, 1-locular; placentae 4 or 5, parietal; stylar region short; stigma disciform-capitate; sterile zone between female and male zones cylindric, ca. 1 cm × 6 mm; sterile male flowers: synandrodes depressed obpyramidal, apex subtruncate; male zone yellowish, cylindric, ca. 3.5 cm × 7 mm; male flowers 8-11-androus; thecae oblong-linear, dehiscing by apical pore; appendix pale yellowish, narrowly conic, ca. 3.5 × 0.5 cm, rugose at base. Berry not seen. Fl. Mar-Jun.

By streams at humid forest margins; 1000-1100 m. Yunnan (Mengla) [Laos, N Myanmar (Bhamo), N Thailand].