Trichomanes lineolatum (Bosch) Hook.
Family: Hymenophyllaceae
Trichomanes lineolatum image
Plants on rock. Stems long-creeping, threadlike, bearing scattered leaves, covered with dark hairs of 2 types, 2-celled glandular hairs and elongate rhizoidlike hairs; roots absent. Leaves round to obovate, simple to irregularly lobed, 1--3 × 0.5--1.5 cm, with dark stellate hairs on margin, 2-celled glandular hairs on petioles and veins, and dark rhizoidlike hairs on petioles; petioles shorter than blades. Venation repeatedly forking from the base; unconnected false veins few or absent. Soral involucres 1--5 per leaf, terminal on blades, narrowly conic, not flaring at mouth; involucre lips with conspicuous dark marginal band 2--5 cells wide. Gametophytes unknown, presumed to be as others of subgenus. 2 n = 68. On rock in limestone sinks; below 10 m; Fla.; Mexico; West Indies; Central America; South America. Trichomanes lineolatum leaves have unusually thick veins that are enlarged toward the margin and conspicuous in dried specimens.