Asplenium monanthes |
Asplenium adiantum-nigrum |
|
---|---|---|
single-sorus fern, single-sorus spleenwort |
black spleenwort |
|
Roots | not proliferous. |
not proliferous. |
Stems | erect, unbranched; scales black with lighter margins, linear-lanceolate, 3–6 × 0.4–0.8 mm, margins entire. |
ascending or short-creeping, infrequently branched; scales dark brown to blackish throughout, narrowly deltate, 2–4(–5) × 0.2–0.5 mm, margins entire or shallowly denticulate to serrulate. |
Leaves | monomorphic. |
monomorphic. |
Petiole | reddish brown throughout, lustrous, 1–12(–20) cm, 1/3–1/10 length of blade; indument of black filiform scales. |
dark reddish brown proximally, often fading to green distally, lustrous, 2–20 cm, 2/3–2 times length of blade; indument of black filiform scales and minute hairs. |
Blade | linear, 1-pinnate throughout, 5–25(–40) × 1–2.5(–3) cm, thick, glabrous; base gradually tapered; apex acute, not rooting. |
deltate, 2–3-pinnate, 2.5–10 × 2–6.5 cm, thick, hairs dark, scattered, minute; base truncate; apex acute to acuminate, not rooting. |
Pinnae | in 10–40 pairs, oblong to quadrangular, somewhat asymmetric; medial pinnae 4–15 × 2–5 mm; base rounded to cuneate; margins crenulate or ± entire; apex obtuse. |
in 4–10 pairs, deltate to lanceolate; most proximal (largest) pinnae 1.5–4 × 1–2.5 cm; base obliquely obtuse; segment margins coarsely incised; apex acute. |
Veins | free, obscure. |
free, evident. |
Sori | 1(–3) per pinna, only on basiscopic side. |
1–numerous pairs per pinna [1–6 pairs per segment], on both basiscopic and acroscopic sides. |
Spores | 32 per sporangium. |
64 per sporangium. |
Rachis | reddish brown throughout, lustrous, glabrous. |
greenish throughout or sometimes reddish brown proximally, lustrous, sparsely pubescent. |
n | = 2n = 108 (apogamous). |
|
2n | = 144. |
|
Asplenium monanthes |
Asplenium adiantum-nigrum |
|
Habitat | Rock | Cliffs |
Elevation | 50–1000 m (200–3300 ft) | 1675–2300 m (5500–7500 ft) |
Distribution |
AL; AZ; NC; SC; HI; Mexico; Central America; West Indies in Hispaniola; Jamaica; South America to n Argentina; Africa including Madagascar; Madeira; Réunion; Tristan da Cunha
|
AZ; CO; UT; Eurasia; Africa |
Discussion | Asplenium adiantum-nigrum is principally a Eurasian species and occurs extremely rarely in North America (see M. G. Shivas 1969 and M. D. Windham 1983 for a discussion of the conspecificity of Western Hemisphere and Eastern Hemisphere material). It is an allotetraploid derived from hybridization of two European taxa, A. cuneifolium Viviani and A. onopteris Linnaeus (M. G. Shivas 1969). Hybrids involving A. adiantum-nigrum and other Asplenium species occur in Europe but are unknown in North America. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 2. | FNA vol. 2. |
Parent taxa | Aspleniaceae > Asplenium | Aspleniaceae > Asplenium |
Sibling taxa | ||
Synonyms | A. andrewsii, A. chihuahuense, A. dubiosum | |
Name authority | Linnaeus: Mant. Pl. 1: 130. (1767) | Linnaeus: Sp. Pl. 2: 1081. (1753) |
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