盾形单叶假脉蕨 dun xing dan ye jia mai jue

Trichomanes tahitense Nadeaud, Énum. Pl. Tahiti, 18. 1873; Microgonium omphalodes Vieillard & E. Fournier; M. tahitense (Nadeaud) Tindale; T. omphalodes (Vieillard & E. Fournier) C. Christensen.

Plants small, circular in outline. Rhizome densely covered with dark brown multicellular hairs, rootless. Laminae closely spaced, simple, sessile, peltate, directly on rhizome, subcircular in outline, 1-3 cm in diam., slightly crisped at margin or irregularly lobed to 1/3-2/3. Veins 2 or 3 times pinnately divided, or further dichotomously branching, finally lacking tracheids and becoming false veinlets; abaxial surface of fronds with many dark brown hairs along veins and false veins. Sori 1-5, sparsely terminal on true veins running to lamina margin, projecting from margin; involucres tubular with dilated mouth, 2-3 × ca. 2 mm, bilabiate; receptacles projecting, filiform. 2n = 68.

On wet rocks or on tree trunks along streams in densely forested lowlands; 100-700 m. E, N, and S Taiwan [Indonesia (Java), Japan, Malesia, Vietnam; Australia, Pacific islands (Melanesia, Micronesia, Polynesia)].