稀齿楼梯草 xi chi lou ti cao

Elatostema approximatum Weddell; E. densiflorum Franchet & Savatier; E. nipponicum Makino.

Herbs dioecious, 2.5-5 cm tall. Stems erect, simple, crispately pubescent. Leaves alternate; nanophylls 3-5 mm. stipules narrowly triangular, 1-1.5 × 0.4-0.5 mm, glabrous, without cystoliths; petiole 0-1 mm; leaf blade obliquely rhombic-obovate, 1-3.5 × 0.5-1.5 cm, thinly herbaceous, major basal lateral veins both arising at base of leaf blade, abaxial surface puberulent along nerves, adaxial surface sparsely strigillose, cystoliths conspicuous or obscure, sparse; base with broader half rounded, margin dentate with 2-5 teeth, apex acute or obtuse. Female inflorescences solitary, 2-4 mm in diam., sessile; receptacle 2.5-4 mm in diam.; bracts triangular; bracteoles spatulate-linear. Achenes ovoid, 8-ribbed. Fl. Jun-Jul.

Valley forests, precipices; 1200-1400 m. S Yunnan [Japan, Korea, India, Indonesia, Laos, Sikkim].