Adiantum tenerum Sw.
Descripción
Rhizomes short-creeping, 5–10 mm diam.; rhizome scales ferrugineous, becoming dark brown in center portion (and so somewhat bicolorous), lustrous, 2–3 X 0.8–1 mm, margins ciliate-fimbriate; fronds clumped, 25–110 cm long, laxly arching; stipes atropurpureous to blackish, lustrous, 10–55 cm X 1.5–3(–4) mm, 1⁄3–1⁄2 the frond length, glabrous or with rare minute tubercles; blades ovate-deltate, 3–5-pinnate proximally, 18–15 X (15–)20–40 cm wide; rachises atropurpureous, glabrous, somewhat flexuous toward tips; pinnae 5–9 compound pairs, alternate, stalked to 4 cm, gradually tapering distally; pinnulets trapeziform to rhombic, or flabellate at blade and pinna apices, fertile pinnulets 1–2 cm long and wide, cuneate at bases, denticulate cleft or lobed distally, sterile pinnulets somewhat larger than the fertile ones, stalked 2–4 mm, stalk color stopping abruptly at bulge at pinnulet bases, articulate; veins free, forking, ending in marginal teeth; indument absent on both blade surfaces, blades sometimes glaucous abaxially; idioblasts absent; sori to ca. 12 per pinnulet, confined to distal margins, with slight yellow farina among sporangia; indusia 1–3 mm long, reniform to oblong, glabrous; 2n=60 (USA, Ver, CR, Jam).
A
A
Forma de vida
TerrestreA
Ejemplar revisado
Camp (Martínez S. 27319, XAL). Chis (Breedlove 23073, DS, NY). Hgo (Gimate 948, ENCB, NY). NL (Aguirre C. 648, ENCB). Oax (Mickel 5818, NY, UC). Pue (Knobloch 696, ENCB, US). Qro (Rzedowski 42853, IEB). QR (Torres 23, 33, CIQRO, MEXU). SLP (Pringle 3360, BR, DS, NY, P, UC, US). Tab (Cowan 3163, CAS, ENCB). Tam (Dressler 1888, UC). Ver (Copeland herb. 116, MICH, P, UC). Yuc (Calzada et al. 6702, UC, XAL).
Unverified, Doubtful, or Mistaken Reports. Tres Marias (Nelson 4281, US, cited by Lenz, 1995, as A. tenerum, and Ferris 5704, DS, and Mason 1822, CAS, cited by Lenz as A. trapezoides, but none verified, all three probably misidentifications).
A
Unverified, Doubtful, or Mistaken Reports. Tres Marias (Nelson 4281, US, cited by Lenz, 1995, as A. tenerum, and Ferris 5704, DS, and Mason 1822, CAS, cited by Lenz as A. trapezoides, but none verified, all three probably misidentifications).
A
Elevación
50 – 1350 mA
Ecología y Hábitat
Woods along streams, coffee plantations, calcareous cliffs.A
Tipo de vegetación
Selva alta, Selva medianaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Adiantum tenerum most closely resembles A. amplum, from which it differs by having smaller, bicolorous rhizome scales, serrulate sterile pinnulets, and the generally more flabellate pinnulets. They also differ in general distribution, A. tenerum being an Atlantic slope species and A. amplum a Pacific slope species. Adiantum tenerum is very common in Veracruz and Chiapas, but less common elsewhere. A specimen cited by Díaz-Barriga and Palacios-Rios (1992) from Michoacán (Hinton 15956, ENCB) is A. amplum.A