Adiantum

• Authority

  Proctor, George R. 1989. Ferns of Puerto Rico and the Virgin Islands. Mem. New York Bot. Gard. 53: 1-389.

• Family

  Pteridaceae

• Scientific Name

  Adiantum

• Description

  Species Description - Tenestrial fems of forest slopes, shady ravines, and rocky banks. Rhizomes short and suberect to slender and wide-creeping, bearing numerous nanow scales especially near the apex. Fronds usually distichous, densely clustered to widely spaced, monomorphic; stipes wiry, dark, and usually highly lustrous. Blades suberect to deflexed or drooping, 1- to 5-pinnate (rarely simple), of various pattems of dissection, glabrous to minutely pubescent or distantly stellate-scaly, sometimes more or less glaucous beneath, rarely glandular or farinaceous. Pinnules sessile or stalked, often articulate, deciduous in some species, in texture membranous to coriaceous, with veins free in most species, often ffabellately branched, or in a few species reticulate. Sori appearing marginal, in fact the sporangia are b o m e along (and sometimes between) the distal ends of ultimate veins, on the underside ofthe sharply reffexed, membranous margin (herein called the "indusioid ffap") ofthe pinnules or segments; paraphyses absent. Annulus of about 18 cells; spores tetrahedral to globose, trilete, smooth to slightly granulate or papillate.

• Discussion

  Type Species. Adiantum capillus-veneris Linnaeus, of almost worldwide distribution except in very cold regions.

  A large pantropical genus of perhaps nearly 200 species, most numerous in South America, a few occurring or extending into temperate regions. Many of them are commonly called "maidenhair fems." The generic name Adiantum is of Greek origin and means un wetted, referring to the rain-shedding texture ofthe foliage in many species.