白序楼梯草 bai xu lou ti cao

Herbs perennial, monoecious, 25-80 cm tall. Stems ascending, simple, glabrous. Leaves alternate; nanophylls absent; stipules subulate or narrowly lanceolate, 2-3 × 0.2-0.4 mm, glabrous, without cystoliths; petiole 1-3 mm; leaf blade obliquely elliptic, 3-6.5 × 1-3 cm, herbaceous, major basal lateral veins asymmetric, 1 basal, the other arising above base, abaxial surface glabrous, adaxial surface sparsely strigillose, cystoliths obscure, sparse; base with broader half auriculate, margin denticulate, apex short acuminate. Male inflorescences solitary, simple, 7-9 mm in diam.; peduncle ca. 6.5 cm; receptacle ca. 7 mm in diam.; bracts connate, ca. 1.5 mm; bracteoles narrowly linear. Female inflorescences solitary, 2-3 mm in diam.; peduncle ca. 0.5 mm; receptacle oblong, ca. 3 × 1.5 mm; bracts triangular; bracteoles elliptic or linear. Male flowers 5-merous. Achenes ellipsoid, 5-ribbed. Fl. Jul-Aug.

* Shaded wet areas in montane forests. S Sichuan.