Adiantum seemannii Hook.
Descripción
Rhizomes short-creeping, rather compact, 5–10 mm diam.; rhizome scales castaneous, concolorous, entire to minutely denticulate; fronds clumped, mostly 30–70 cm long, arching; stipes atropurpureous to black, to 45 cm X 3 mm, glabrous except at bases; blades ovate to deltate, 1-pinnate or some specimens 2-pinnate proximally, each blade with a ± conform terminal pinna; rachises atropurpureous to black, glabrous; pinnae 1–4 pairs, broadly ovate, mostly 5–10 X 2.5–6 cm, rounded at bases, acuminate at apices, serrate (sterile) to entire (fertile), with stalks 1–3 cm long, stalk color stopping abruptly at pinna bases, pinnae not articulate; pinnules absent on pinnae, or the proximal pinna pair 1-pinnate; veins free, forking, ending in sharp teeth on sterile pinnae/pinnules; indument absent on both surfaces, blades often glaucous abaxially; idioblasts present on both blade surfaces, more conspicuous adaxially; sori linear, usually interrupted (but contiguous) on both acroscopic and basiscopic margins of pinnae or pinnules; indusia mostly 5–20 mm long, especially near bases of pinnae/pinnules, glabrous.A
Forma de vida
TerrestreA
Ejemplar revisado
Chis (Breedlove 31586, DS, NY, 34206, DS; Croat 43786, CAS, ENCB, MO; Sohns 1615, MEXU, US).A
Elevación
200 – 450 mA
Ecología y Hábitat
On steep rocky slopes.A
Tipo de vegetación
Selva altaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC
Discusión taxonómica
Adiantum seemannii is readily distinguished from congeners in Mexico by the 1-pinnate blades, relatively few lateral pinnae (1–4 pairs), and large, ovate pinnae 5–10 cm long. It is related to species in South America, e.g., A. platyphyllum Sw., from Ecuador to Bolivia and southern Brazil.A