Asplenium resiliens

Roots not proliferous. Stems erect, unbranched; scales black throughout, linear-lanceolate, 4–5 × 0.2–0.6 mm, margins entire. Leaves monomorphic. Petiole black throughout, lustrous, 1.5–3(–5) cm, 1/4–1/10 length of blade; indument of blackish brown, filiform scales. Blade linear to narrowly oblanceolate, 1-pinnate throughout, 9–20(–30) × 1–2(–2.5) cm, thick, glabrous; base gradually tapered; apex acute, not rooting. Rachis black throughout, lustrous, glabrous. Pinnae in 20–40 pairs, oblong; medial pinnae (5–)10–20 × (2–)3–5 mm; base usually with an acroscopic auricle; margins ± entire to shallowly crenate; apex obtuse. Veins free, obscure. Sori 2–5 pairs per pinna, on both basiscopic and acroscopic sides, often confluent with age. Spores 32 per sporangium. n = 2n = 108 (apogamous).

Habitat: Cliffs, sinkholes, on limestone or other basic rocks
Elevation: 100–1500 m

Ala., Ariz., Ark., Del., Fla., Ga., Ill., Kans., Ky., La., Md., Miss., Mo., N.Mex., Nev., N.C., Okla., Pa., Tenn., Tex., Utah, Va., W.Va., Mexico, West Indies in Hispaniola, Jamaica, Central America in Guatemala, South America.

Discussion

Asplenium parvulum M. Martens & Galeotti is an older, but illegitimate, name because it is a later homonym of A. parvulum Hooker.

In Florida Asplenium resiliens hybridizes with A. heterochroum Kunze (4 x), producing A. × heteroresiliens (5 x).

Selected References

None.

Lower Taxa