Argyrochosma delicatula (Maxon & Weath.) Windham
Descripción
Rhizomes compact, horizontal or ascending; rhizome scales 4–6 X 0.2–0.3 mm, linear, concolorous, orange-brown to dark brown, entire; fronds (6–)10–25(–35) cm long, clumped; stipes nearly half the frond length, castaneous to atropurpureous, lustrous, glabrous, terete; blades mostly deltate, tripinnate to subquadripinnate, herbaceous; rachises terete; pinnae 4–8 pairs; segments rhombic, oblong, or orbicular, 1–2(–3) mm across, segments articulate where the dark color of the stalk abruptly terminates at the base of the segments; abaxial surfaces with pale yellow farina; adaxial surfaces sparsely farinose; sori borne on the distal 1⁄2 of the veins, margins unmodified; sporangia 64-spored; 2n=54 (NL).A
Ejemplar revisado
Chih (Jones s.n., 12 Sep 1903, UC). Coah (Johnston et al. 11506, LL). NL (Hinton et al. 21025, 21597, 23260, TEX; Palmer 1386, GH, P, US; Pray 3029, LAM; Pringle 2581, B, BM, CAS, GH, K, LL, MEXU, MICH, MO, MSC, NY, P, UC, US; Windham 482, NY).A
Elevación
900 – 2230 mA
Ecología y Hábitat
Exposed or shaded rocky places, limestone ledges, shady slopes.A
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
This species is not entirely distinct from Argyrochosma incana, although from the few collections available it seems sufficiently so. Possibly it is a geographic variant of that species. R. Tryon (1956) distinguished A. delicatula from A. incana by the former having scattered adaxial farina, whereas A. incana was thought to be glabrous adaxially. Specimens of A. incana with adaxial farina occur sporadically throughout the range of the species. Argyrochomsa delicatula is best distinguished on the basis of its very small segments, thinner texture, and pale yellow farina.
This species was not reported by Windham in FNA Ed. Comm., 1993, but a specimen at NY (Lemmon s.n., 23 Apr 1880, from southeastern Arizona), formerly determined as A. incana, has the small, thin segments with pale yellow farina characteristic of A. delicatula. Other records of A. incana from Arizona should be critically examined.
A
This species was not reported by Windham in FNA Ed. Comm., 1993, but a specimen at NY (Lemmon s.n., 23 Apr 1880, from southeastern Arizona), formerly determined as A. incana, has the small, thin segments with pale yellow farina characteristic of A. delicatula. Other records of A. incana from Arizona should be critically examined.
A