Adiantum capillus-veneris
Adiantum aleuticum
black maidenhair fern, common maidenhair, southern maiden-hair, southern maidenhair fern, Venus hair, Venus hair fern, Venus's-hair fern
adiante des aléoutiennes, Aleutian maidenhair, five-finger fern, maidenhair fern, northern maiden-hair, northern maidenhair fern, western maidenhair, western maidenhair fern
short-creeping;
scales golden brown to medium brown, concolored, iridescent, margins entire or occasionally with single broad tooth near base.
short-creeping or suberect;
scales bronzy deep yellow, concolored, margins entire.
lax-arching or pendent, closely spaced, 15–75 cm.
lax-arching to stiffly erect or pendent, often densely clustered, 15–110 cm.
0.5–1.5 mm diam., glabrous, occasionally glaucous.
0.5–3 mm diam., glabrous, often glaucous.
lanceolate, pinnate, 10–45 × 4–15 cm, glabrous, gradually reduced distally;
proximal pinnae 3(–4)-pinnate;
rachis straight to flexuous, glabrous, not glaucous.
fan-shaped to funnel-shaped, pseudopedate, 1-pinnate distally, 5–45 × 5–45 cm;
proximal pinnae (1–)2–7-pinnate;
rachis straight, glabrous, often with glaucous bloom.
various, generally cuneate or fan-shaped to irregularly rhombic (plants in American southwest occasionally with segments nearly round), about as long as broad;
base broadly to narrowly cuneate;
margins shallowly to deeply lobed, incisions 0.5–7 mm, occasionally ± laciniate, sharply denticulate in sterile segments;
apex rounded to acute.
oblong, long-triangular, or occasionally reniform, ca. 2.5–4 times as long as broad;
basiscopic margin straight to oblique, or occasionally excavate;
acroscopic margin lobed, lobes separated by narrow to broad incisions 0.2–3 mm wide;
apex acute to obtuse, obtuse apices divided into ± angular lobes separated by sinuses 0.6–4 mm deep, margins of lobes sharply denticulate.
transversely oblong or crescent-shaped, 1–3(–7) mm, glabrous.
transversely oblong to crescent-shaped, 0.2–3.5(–6) mm, glabrous.
mostly 40–50 µm diam. 2n = 120.
mostly 37–47 µm diam. 2n = 58.
stalks 0.5–3.5 mm, dark color extending into segment base.
stalks 0.2–0.9(–1.3) mm, dark color entering into segment base or not.
Adiantum capillus-veneris
Adiantum aleuticum
No evident pattern to morphologic variation in the species is discernible, although a number of segregate species and infraspecific taxa have been recognized within North American Adiantum capillus-veneris. In the Eastern Hemisphere, the species is diploid, with 2n = 60 (I. Manton 1950). Several tetraploid counts have been reported from North America (W. H. Wagner Jr. 1963). Spore-measurement data suggest, however, that the polyploid cytotype may not be widely distributed. Further investigation is needed to determine whether Adiantum capillus-veneris populations in North America are conspecific with those in Eurasia and Africa.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Adiantum aleuticum is disjunct in wet rock fissures at high elevations in Arizona, Colorado, Montana, Nevada, Utah, Wyoming, and Mexico in Chihuahua, and it is disjunct on serpentine in Newfoundland, Quebec, Maine, Maryland, Pennsylvania, and Vermont.
Although the western maidenhair has traditionally been interpreted as an infraspecific variant of Adiantum pedatum, the two taxa are reproductively isolated and differ in an array of morphologic characteristics. Therefore, they are more appropriately considered separate species (C. A. Paris and M. D. Windham 1988). Morphologic differences between A. pedatum and A. aleuticum are subtle; the two may be separated, however, using characteristics in the key. Adiantum aleuticum occurs in a variety of habitats throughout its range, from moist, wooded ravines to stark serpentine barrens and from coastal cliffs to subalpine boulder fields. Although morphologic differences exist among populations in these diverse habitats, they are not consistent. Consequently, infraspecific taxa are not recognized here within A. aleuticum.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
LA Plants
MO Plants
SW CO Wildflowers- Local floras:
BC, 
CA, 
OR, 
WA - Local Web sites: CalFlora, CalPhotos,
Flora NW, 
Go Botany, 
MD Biodiversity, 
PNW Herbaria 
WildflowerSearch
iNaturalist (observations)
USDA Plants Database- LBJ Wildflower Center
- SEINet
- Plants of the World Online
- Encyclopedia of Life
- Wikipedia
- Google Image Search
