Description from Flora of China
Lycopodium uncinatum Desvaux ex Poiret in Lamarck, Encycl., Suppl. 3: 558. 1814; L. dilatatum Hooker & Greville; Lycopodioides uncinata (Desvaux ex Poiret) Kuntze; Selaginella eurystachya Warburg.
Plants terrestrial, evergreen; main stem scandent from erect base, 50-100 cm or more. Rhizophores restricted to lower part of stem or at intervals throughout length of main stem, borne on ventral side in axils of branches. Main stems branched from near base upward, pinnately branched, stramineous, 1-1.5 mm in diam. in lower part, terete and angulate, sulcate, glabrous, apex of main stems flagelliform, branches many; primary leafy branches 5-8 pairs, twice pinnately branched, secondary branches once or twice forked, branchlets dense, adjacent primary branches on main stem 5-8 cm apart, ultimate branches 3.8-6 mm wide including leaves. Leaves often iridescent, distinctly white-margined, margin entire. Axillary leaves on main stems obviously larger than those on branches, reniform, ca. 3 × 4 mm, base slightly cordate; axillary leaves on branches symmetrical, broadly elliptic or orbicular, 2.2-2.8 × 0.8-2.2 mm, base subcordate, margin entire. Dorsal leaves asymmetrical, those on main stems obviously larger than those on branches; dorsal leaves on branches approximate to imbricate, parallel to axis or overlapping at leaf apex and often reflexed, ovate, 1-2.4 × 0.6-1 mm, not carinate, base obtuse, margin entire, apex long acuminate. Ventral leaves asymmetrical, those on main stem obviously larger than those on branches; ventral leaves on branches contiguous, spreading, oblong, 2.2-3.2 × 1-1.6 mm, margin entire, apex acute or mucronate; basiscopic base rounded; acroscopic base not enlarged. Strobili solitary, terminal, compact, tetragonal, 5-25 × 2.5-4 mm; sporophylls uniform, white-margined, ovate-triangular, carinate, margin entire, apex acuminate; megasporophylls in basal portion on lower side of strobilus or megasporophylls in middle or upper portion on lower side; microsporangia transversely elliptic, rather thin, cells regular; microspores pale yellow, megaspores gray-white or dark brown.
● Damp ground under shrubs along rivers or on forest floor, also cultivated and sometimes escaped; below 100-1200 m. Anhui, Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan, Taiwan, Yunnan, Zhejiang.