Asplenium arcanum A.R.Sm.
Descripción
Roots fibrous, not proliferous; rhizomes erect; rhizome scales blackish, clathrate, very narrow, 1–2 X 0.1–0.2 mm, entire; fronds clustered, mostly 7–20 cm long; stipes atropurpureous at least at bases, greenish distally, 1–12 cm X 0.3–0.6 mm, 1⁄2–2⁄3 of frond length, essentially lacking hairs or scales except at bases, not winged; blades membranaceous, bipinnate-pinnatifid, 2–10 X 3–9 cm, deltate to pentagonal, apices pinnatifid, nonproliferous; rachises abaxially green or purple-streaked at the bases, lacking scales, adaxial wings 0.1–0.2 mm wide; pinnae 1–5 pairs, proximal pair largest, 2–5 X 1.5–3 cm, inequilateral, exaggerated basiscopically, sessile or stalked to 2 mm, long-acuminate, deeply lacerate, distal pinnae slightly adnate, segments or pinnules lacerate or toothed at tips; veins 1-forked, easily visible, tips evident adaxially; indument abaxially of scattered, appressed, light tan, hairs 0.1–0.2 mm long on veins and tissue between veins; sori 1–3 pairs per segment on both sides of segment midveins; indusia 2–5 X 0.5–0.8 mm, margins erose; spores reniform.A
Forma de vida
TerrestreA
Ejemplar revisado
Nay (Wright 1360, DS, GH, MO). Sin (Breedlove 35626, CAS, MO, 35642, CAS; Mexia 257, MO, 257a, UC; Pray 1801, NY). Note: Mexia 257 (UC) is A. tenerrimum.
A
A
Distribución
México (Country) endemicB
Elevación
200–700 mA
Ecología y Hábitat
On stream banks and wooded slopes.A
Categoría IUCN
No incluidaC
Categoría NOM-059-SEMARNAT-2010
No incluidaD
Discusión taxonómica
This species has previously been determined as A. cf. Fournieri(=A. tenerrimum), an extremely dissected form of A. pumilum (where it was treated as a variety by Davenport), or A. fragrans. It is more or less intermediate between the two first-named species and could have arisen through hybridization. However, specimens of A. arcanum seem to have well formed spores. Breedlove 35626 was previously determined as A. minimum vel aff. by Adams at CAS and as A. tenerrimum by Adams at MO.A