2. Lygodium circinnatum (N. L. Burman) Swartz, Syn. Fil. 153. 1806.
海南海金沙 hai nan hai jin sha
Ophioglossum circinnatum N. L. Burman, Fl. Indica, 228. 1768; Hydroglossum circinnatum (N. L. Burman) Willdenow; H. pedatum (N. L. Burman) Willdenow; Lygodium basilanicum Christ; L. conforme C. Christensen; L. dichotomum (Cavanilles) Swartz; L. pedatum (N. L. Burman) Swartz; O. pedatum N. L. Burman; Ugena dichotoma Cavanilles; U. macrostachya Cavanilles.
Rhizome shortly creeping, bearing stipes very close together, apex of rhizome and bases of stipes densely covered with black hairs. Juvenile fronds once dichotomous, each branch bearing a pedate-palmatisect pinna, lobes usually ca. 4 or 5, subequal, up to ca. 25 × 3.5 cm, midrib of an outer lobe arising near base of next inner lobe, surfaces glabrous but conspicuously warty when dry (not when living), veins uniting with thickened margin, margins entire, often somewhat crisped, pale and much thickened (translucent when living), apices acute to acuminate. Rachis of climbing frond up to ca. 10 m, 2-5 mm in diam., glabrous; primary rachis branches very short, with sunken dormant apex covered with pale hairs not thickened at base; secondary rachis branches simple and 2-6 cm, or once dichotomous with each branch 1-2 cm beyond fork; sterile pinnae usually with 2-6 subequal diverging lobes separate to within ca. 2 cm from base, surfaces nearly always warty when dry, base cuneate or truncate, margin pale and thickened, entire; fertile secondary rachis branches simple or 1-3 times dichotomous (rarely subpinnate); fertile pinnae usually sessile in pairs at ends of ultimate branches, or members of a pair partly fused at base, less often 3-5-lobed (always so if secondary rachis simple), lamina ± reduced and commonly 3-6 mm wide, rarely less than ca. 2 mm or approximating in width to sterile pinna lobes; sorophores 2-5 mm, sessile; spores finely and evenly verrucose, laesura prominent.
Slightly shaded places in primary or secondary forests, never where ground becomes seasonally very dry; near sea level to 1500 m. Guangdong, Guangxi, Guizhou, Hainan, Yunnan [Cambodia, E India, Laos, Malaysia, Sri Lanka, Vietnam; Australia, W Pacific islands].