Description from Flora of China
Plants annual, small, terrestrial or on rocks. Rhizomes short, poorly developed, sparsely scaly; scales small, fibrous. Fronds many, monomorphic, tufted; stipe chestnut-colored or chestnut-brown, slender, rounded abaxially, grooved adaxially, glabrous; lamina ovate, ovate-deltoid to ovate-lanceolate, or lanceolate, 1-3-pinnate, thinly herbaceous or submembranous, both surfaces usually glabrous. Ultimate pinnules or segments small, ovate-elliptic, spatulate, or obovate, margin entire, or shallowly lobed at apex. Veins free, forked, 1 veinlet per segment, far from frond margins. Indusia absent. Sori borne along veinlets, paraphyses absent. Spores tetrahedral, somewhat ridged on surface. Gametophytes still alive for a long time after sporophytes are produced. x = 29, 58.
About six species: worldwide tropics, subtropics, and Mediterranean region and Europe along Atlantic Ocean; two species in China.
(Authors: Zhang Gangmin (张钢民); Tom A. Ranker)