Asplenium adiantum-nigrum
Asplenium serratum
black spleenwort
American bird's-nest fern, new world bird's-nest fern, wild birdnest fern
not proliferous.
proliferous.
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.
erect, unbranched;
scales brown throughout, narrowly lanceolate, 5–10 × 1–1.5 mm, margins entire.
monomorphic.
monomorphic.
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.
vestigial.
deltate, 2–3-pinnate, 2.5–10 × 2–6.5 cm, thick, hairs dark, scattered, minute;
base truncate;
apex acute to acuminate, not rooting.
linear, oblanceolate, simple, (10–)20–40(–70) × 3–8 cm, thick, glabrous;
base gradually tapered;
margins entire to irregularly crenate;
apex attenuate, not rooting.
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.
free, evident.
numerous, free, mostly immersed.
1–numerous pairs per pinna [1–6 pairs per segment], on both basiscopic and acroscopic sides.
parallel to each other, nearly perpendicular to midrib.
64 per sporangium.
64 per sporangium.
greenish throughout or sometimes reddish brown proximally, lustrous, sparsely pubescent.
green throughout, dull, glabrous.
= 144.
= 144.
Asplenium adiantum-nigrum
Asplenium serratum
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.)
Asplenium serratum is found rarely in southern peninsular Florida, where it is at the extreme edge of its tropical American range. This large simple-leaved spleenwort is called "American bird's-nest fern" because of its superficial resemblance to the Old World A. nidus Linnaeus, which is regularly grown in temperate conservatories. Asplenium serratum is unusual in having roots with abundant, matted hairs rather than scattered hairs as found in other species.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
WildflowerSearch
iNaturalist
USDA Plants Database
