Elatostema pycnodontum W. T. Wang

Herbs perennial, monoecious or dioecious, 10-45 cm. Stems ascending, simple or branched, glabrous. Leaves alternate; nanophylls absent; stipules narrowly ovate or broadly lanceolate, 4-8 × 1.5-3.5 mm, glabrous, without cystoliths; petiole 1-1.5 mm; leaf blade obliquely oblong-lanceolate or rhombic, (1.2-)2.5-6 × 1-2 cm, herbaceous, major basal lateral veins both arising at base of leaf blade, abaxial surface sparsely puberulent along veins, adaxial surface sparsely strigillose, cystoliths conspicuous, dense; base with broader half broadly cuneate or rounded, margin serrate, apex acuminate. Male inflorescences solitary, simple, 1.2-3 mm in diam.; peduncle 0-0.5 mm; receptacle absent; bracts connate, ca. 2.6 mm; bracteoles linear. Female inflorescences solitary, 30-flowered or more, 2-5 mm in diam.; peduncle 1.5-2 mm; receptacle very small; bracts narrowly triangular or lanceolate-linear; bracteoles linear. Male flowers 5-merous. Achenes ovoid, 5-ribbed. Fl. Aug-Sep.

Guizhou, SW Hubei, NW Hunan, NE Yunnan.

* Valley streamsides, dark damp places; 800-1100 m.

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

密齿楼梯草（学名：Elatostema pycnodontum）为荨麻科楼梯草属的植物，是中国的特有植物。分布于中国大陆的湖北、云南、湖南、贵州等地，生长于海拔800米至1,100米的地区，常生长在山谷沟边以及岩洞中阴处，目前尚未由人工引种栽培。