Cheilanthes covillei Maxon
Descripción
Rhizomes short-creeping, horizontal, 2–4 mm diam.; rhizome scales lanceolate to linear-lanceolate, concolorous, dark brown to black, sclerotic, often weakly bicolorous with narrow, tan margins, ca. 2 mm long, entire; fronds to 30 cm long, clumped; stipes dark reddish brown to atropurpureous, lustrous, terete, with scattered linear-lanceolate whitish scales to 3 mm long; blades lanceolate to ovate, 3–4-pinnate, 1.5–5 cm wide; pinnae ca. 10 pairs, equilateral; segments bead-like, 1–3 mm long; adaxial segment surfaces glabrous; abaxial segment surfaces glabrous or with a few scales near segment base, costal scales ovate-lanceolate, whitish with castaneous base, cordate with overlapping lobes, 2–3 X 0.4–1.5 mm, strongly imbricate, ciliate only on basal lobes, usually concealing ultimate segments and exceeding them; laminar margins recurved and weakly differentiated, entire; sporangia 64-spored; spores brown; 2n=60 (USA).A
Ejemplar revisado
BCN (Carter 2555, MEXU, UC; Gentry & Cech 8910, MEXU; Moran 7997, MEXU, US, 11394, MEXU, 10297, DS, 14607, US, 11543, UC, US, 20960, DS; Wiggins 9898, UC).A
Elevación
650 – 2200 mA
Ecología y Hábitat
Rocky slopes, cliffs, and ledges, usually on igneous substrates.A
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Cheilanthes covillei differs from C. clevelandii by having glabrous blades and costal scales ciliate only on the basal lobes. It is distinct from the much rarer in Mexico C. fendleri by having rigid, dark brown, strongly appressed rhizome scales. It hybridizes with C. parryi, C. newberryi, and C. fendleri in the southwestern United States to form rare, sterile diploids.A