Asplenium laetum Sw.
Descripción
Roots fibrous, wiry, not proliferous; rhizomes short-creeping; rhizome scales clathrate, lumina not occluded, 1–2.5 X 0.1–0.3 mm, entire; fronds few, 1–2 mm apart, 15–40 cm long; stipes dark brown, lustrous, 3–16 cm X 1–2 mm, 1⁄5–2⁄5 of frond length, with filiform scales ca. 3 X 0.1–0.2 mm at bases, adaxial wings, if any, ≤ 0.1 mm; blades chartaceous, oblong-lanceolate, 1-pinnate, 10–25 X 3–9 cm, proximal 1–3 pinna pairs slightly reduced, apices pinnatifid, not proliferous; rachises brown, somewhat lustrous, glabrous, adaxially with greenish wings ≤ 0.1 mm wide; pinnae oblong, 12–22 pairs, 2–6 cm X 4–12 mm, stalked 0.5–3 mm, bases inequilateral, strongly excavate basiscopically, occasionally slightly auriculate acroscopically, apices obtuse to usually acute, margins serrate to biserrate; veins 1- or 2-forked, visible on both sides of blades, tips evident adaxially; indument abaxially of whitish appressed hairs 0.1mmlong; sori (2–)4–7(–9) pairs per pinna, occasionally diplazioid, on both sides of costae; indusia 4–10 X 0.3–0.8 mm, margins erose; spores reniform, 64 per sporangium (Murakami & Moran, 1993); 2n=72 (Jam).A
Forma de vida
TerrestreA
Ejemplar revisado
Chis (Breedlove 22506, DS, 55423, CAS; Purpus 7241, UC, US). Oax (Hernández G. 1008, CHAPA, MO, 1787, NY; Mickel 7188, UC). Tab (Cowan & Magaña 3139, CAS, ENCB, MEXU, MO, NY; Gilly & Hernández X. 278, US). Ver (Dorantes 2555, UC; Purpus 2846, UC).
Unverified, Doubtful, or Mistaken Reports. SLP (reported by Mickel & Beitel, 1988, but not verified).
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Unverified, Doubtful, or Mistaken Reports. SLP (reported by Mickel & Beitel, 1988, but not verified).
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Elevación
(100–)1000–1600 mA
Ecología y Hábitat
On wet rocks near streams.A
Tipo de vegetación
Selva altaA
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
Asplenium laetum differs from A. harpeodes in its creeping rhizomes, much smaller rhizome scales (1.5–2.5 mm long), fewer pinnae (10–19 pairs), pinna apices acute to obtuse, terrestrial or epipetric habit, and occurrence at lower elevations. Hernández G. 1008 is very atypical in the prominently auriculate pinnae (auricles to 6 mm long), biserrate pinna margins, and broad pinnae 2 cm wide, including auricles (pinnae to 1.4 cm wide, excluding auricles).
Hallberg 1467 (NY), from Oaxaca, was cited as the hybrid between A. laetum and A. hoffmannii by Murakami and Moran (1993), but this specimen seems reasonably typical A. laetum to us, especially in the atropurpureous, lustrous stipes and rachises, pinna shape and cutting, and blade texture. The spores, said by Murakami and Moran to be abortive, appear mostly well formed to us. The putative hybrid between A. hoffmannii and A. laetum, called A. incisoserratum (Rosenst.) Murakami & R. C. Moran, was said to occur in southern Mexico (only the above-mentioned specimen cited), Costa Rica, Trinidad, and Colombia.
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Hallberg 1467 (NY), from Oaxaca, was cited as the hybrid between A. laetum and A. hoffmannii by Murakami and Moran (1993), but this specimen seems reasonably typical A. laetum to us, especially in the atropurpureous, lustrous stipes and rachises, pinna shape and cutting, and blade texture. The spores, said by Murakami and Moran to be abortive, appear mostly well formed to us. The putative hybrid between A. hoffmannii and A. laetum, called A. incisoserratum (Rosenst.) Murakami & R. C. Moran, was said to occur in southern Mexico (only the above-mentioned specimen cited), Costa Rica, Trinidad, and Colombia.
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