Argyrochosma (J. Sm.) Windham
Descripción
Usually epipetric; rhizomes compact, horizontal to ascending, usually unbranched; rhizome scales tan to brown, concolorous, linear to lanceolate, margins entire; fronds monomorphic, clumped, 3–30 cm long; stipes castaneous to atropurpureous or black, terete or somewhat flattened adaxially, glabrous except for a few scales near bases; blades lanceolate, ovate, or deltate, 2–6-pinnate, coriaceous to chartaceous; abaxial surfaces usually covered by whitish farina, less commonly glabrous; adaxial surfaces glabrous or sparsely glandular, dull; rachises straight or flexuous; ultimate blade segments stalked or subsessile, usually ecostate, elliptic to ovate or deltate, usually less than 4 mm wide; bases subcordate, stalks lustrous and dark-colored; segments often articulate, deciduous; segment margins plane or recurved; veins of ultimate segments free, usually obscure; false indusia absent, though the unmodified or poorly differentiated margins somewhat recurved; sori borne along veins abaxially, often submarginal; sporangia containing 64 or 32 spores, usually intermixed with farina; spores tetrahedral-globose, brown, with cristate or rugose surfaces; x=27.A
Distribución
México (Country) native and not endemicB
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
Argyrochosma is a genus of about 20 species, all New World. Twelve species occur in Mexico. Molecular data (Gastony & Rollo, 1995) show that Argyrochosma is monophyletic and sister to Pellaea and Astrolepis.A