This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol1", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Blades entire, pinnatifid or lobed, or several times pinnately divided. Indusium tubular or funnel-shaped, truncate or sometimes broadly two-lipped, the sporanges sessile, mostly upon the lower portion of the slender often exserted receptacle. [Greek, in allusion to the delicate hair-like ultimate segments of some of the species.]
About 210 species, mostly tropical. Besides the following, 3 species occur in the southern United States. Type species: Trichomanes crispum L.
Trichomanes Boschianum Sturm; v. d. Bosch.
Ned. Kr. Arch. 52: 160. 1861. Trichomanes radicans of American writers. Not Sw.
Rootstocks filiform, wiry, tomentose, creeping. Stipes (petioles) ascending, l' - 3' long-naked or nearly so; blades 2'-8' long, 8"-l 1/2' wide, membranaceous, lanceolate or ovate-lanceolate, 2-3-pinnatifid; pinnae ovate, obtuse, the upper side of the cuneate base parallel with or appressed to the narrowly winged rachis; segments toothed or cut into linear divisions; indusia terminal on short lobes, 1-4 on a pinnule, the mouth slightly 2-lipped; receptacle more or less exserted, bristle-like, bearing the sessile sporanges mostly near the base.
On wet rocks, Kentucky to Florida and Alabama.