Adiantum patens Willd.
Descripción
Rhizomes short-creeping, 3–5 mm diam.; rhizome scales light brown, ciliate-fimbriate, 2–3 X 0.8–1 mm; fronds clumped, 20–45(–70) cm long, laxly arching; stipes castaneous to atropurpureous, 12–40 cm X 1–2(–3) mm, 1⁄2–2⁄3 the frond length, glabrous except at bases; blades imparipedate, almost round in outline, to 30 X 30 cm, the two proximal pinnae alternate, each appearing 2–3-forked by virtue of unequal basiscopic branching; rachises castaneous, with dense, branched whitish hairs 0.1 mm long; pinnae a single lateral pair plus a terminal one, the lateral ones to 20 cm long, unequally basiscopically branched 2–3 times, the terminal one 1-pinnate, to 25 cm long; pinnulets oblong, rounded to truncate at tips, shallowly lobed to crenate on acroscopic and distal margins, entire on basiscopic margins, subsessile with stalks less than 1 mm long, stalk color passing into pinnulet bases, non-articulate; veins free, forking, ending at the cartilaginous margins; indument on both surfaces of scattered glandular, septate hairs 0.2–1 mm long on veins; idioblasts absent; sori to 10 per pinnulet along acroscopic and distal margins, absent on basiscopic margins; indusia 1–1.5 mm long, lunate to reniform or round-reniform, glabrous.A
Forma de vida
TerrestreA
Ejemplar revisado
Chis (Purpus 7113, UC). Col (Jones 500, UC, US). Dgo (Sánchez 747, MEXU, US). Gro (Mexia 8802a, B, UC). Jal (Pringle 1869, B, BR, DS, K, NY, UC, US). Méx (Hinton 4751, NY). Mich (Díaz Luna 7491, GUADA, UC). Mor (Lyonnet 1374, CAS, ENCB, MEXU, US). Nay (Téllez 12821, IEB, MEXU). Oax (Mickel 6105, NY, UC). Sin (González Ortega 586, ENCB, MEXU). Son (Boutin & Kimnach 3673, NY).A
Elevación
200 – 1900(– 2100) mA
Ecología y Hábitat
On road banks and open woods.A
Tipo de vegetación
Bosque de pino-encinoA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
This species is extremely common on the Pacific slopes in Mexico (e.g., over a hundred collections have been seen from Nayarit and Jalisco alone) but absent elsewhere in the country. The seemingly pedate branching of the fronds and the minute, branching rachis hairs distinguish this species from all others. Although superficially similar to A. aleuticum, which has similar blade architecture, the closest relatives appear to be A. galeottianum and A. shepherdii, which see. A closely related subspecies occurs in Africa, subsp. oatesii (Baker) Schelpe.
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