3. Lecanthus petelotii (Gagnepain) C. J. Chen in C. Y. Wu, Fl. Xizang. 1: 546. 1983.
越南假楼梯草 yue nan jia lou ti cao
Meniscogyne petelotii Gagnepain, Bull. Soc. Bot. France 75: 100. 1928.
Herbs annual, monoecious or dioecious. Stems often simple, 2-10 cm tall, sparsely pubescent or subglabrous. Leaves usually crowded at stem apex; stipules triangular-ovate, 1.5-3 mm; petiole 1-15 mm; leaf blade unequal in same pair, broadly ovate or rhombic-ovate, 0.5-9.5 × 0.3-3 cm, 3-veined, lateral basal pair reaching to distal teeth or anastomosing with adjacent secondary veins before margin, lateral veins 2 or 3 on each side, sparsely hirsute adaxially, sparsely pubescent on veins abaxially, base slightly oblique, broadly cuneate or rounded, margin 3-8-serrate, apex acute or obtuse; cystoliths linear, conspicuous on both surfaces. Male inflorescences few flowered, receptacle cuplike; peduncle 1-5 mm. Female inflorescences on discoid receptacles, 3-6 mm in diam.; peduncle 1-2 cm. Male flowers in bud obovoid, ca. 1 mm; pedicel 1-3 mm; perianth lobes 4, unequal, sometimes corniculate below apex; stamens 4; rudimentary ovary minute, inconspicuous. Female flowers: perianth lobes 4, cymbiform, shorter than ovary, in fruit enlarged and longer than achene, long corniculate below apex; staminodes conspicuous; stigma soon deciduous, penicillate. Achene brown-gray, oblong, slightly compressed, ca. 0.6 mm, U-shaped elevated appendix along distal dorsi-ventral edge, verrucose. Fl. Jun-Aug, fr. Aug-Oct.
Shaded moist places in forests, mossy rocks, along streams; 2500-2900 m. S Xizang, Yunnan [Laos, Vietnam].
Two varieties occur in China; var. petelotii occurs in Laos and Vietnam.