(Willd.) Und., Bull. Torrey Bot. Club 34:260.1907
Free-climbing, vinelike, dichotomously branched herb; rhizome long-creeping, 3-5 mm diam, scabrous from persistent bases of articulate trichomes; primary leaf axes at first erect, eventually arching. Leaflets paired at ultimate nodes, deeply pinnatifid, oblong-lanceolate, mostly 10-25 cm long, l.5-6 cm wide, sessile, glaucous beneath, glabrate, sometimes with a few brown, stellate scales below; lobes 3-6 mm wide, firm, the veins 3-5-forked, somewhat raised; leaf nodes in lower dichotomies rarely with a pair of reduced accessory pinnae. Sori round, exindusiate, in 2 rows, l row on each side of midrib on underside of lobes, each sorus bearing more than 6 sporangia. Croat 4829.
Locally abundant on steep, eroding banks on the shore, particularly on the northern shore of Orchid Island and on Gross Point.
For a description of branching in this genus, see Underwood (1907).
Mexico to Brazil, the Guianas, and Bolivia; West Indies. In Panama, known principally from tropical moist forest in the Canal Zone, San Blas, Herrera, Panama, and Darien; known also from tropical dry forest in Panama (Taboga Island) and from tropical wet forest in Colon.