Elatostema megacephalum W. T. Wang

Herbs perennial, dioecious, 50-100 cm tall. Stems erect, simple, glabrous. Leaves alternate; nanophylls absent; stipules lanceolate or broadly lanceolate, 10-18 × 2.5-3 mm, glabrous, with cystoliths; petiole 1.5-12 mm; leaf blade obliquely elliptic, 9-25 × 3.5-10 cm, nearly papery or herbaceous, major basal lateral veins asymmetric, 1 basal, the other arising above base, abaxial surface glabrous or sparsely puberulent along nerves, adaxial surface sparsely hirtellous, cystoliths conspicuous, dense; base with broader half broadly cuneate, margin denticulate, apex acuminate. Male inflorescences solitary, simple, 10-25 mm in diam.; peduncle 5-7 mm; receptacle 8-23 mm in diam.; bracts connate, ca. 5 mm wide; bracteoles cymbiform-linear. Female inflorescences solitary, 15-25 × 10-20 mm; peduncle ca. 5 mm; receptacle oblong, 14-23 × 9-18 mm; bracts triangular; bracteoles spatulate-linear. Male flowers 4-merous. Achenes ellipsoid, 8-ribbed. Fl. Feb-May.

C and S Yunnan [Malaysia, Thailand].

Evergreen broad-leaved forests in ravines; 1000-2000 m.

Elatostema mollifolium W. T. Wang.

Elatostema megacephalum là loài thực vật có hoa trong họ Tầm ma. Loài này được W.T.Wang mô tả khoa học đầu tiên năm 1980.

巨序楼梯草（学名：Elatostema megacephalum）为荨麻科楼梯草属的植物，为中国的特有植物。分布于中国大陆的云南等地，生长于海拔1,000米至1,600米的地区，多生于山谷常绿阔叶林中，目前尚未由人工引种栽培。