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black maidenhair fern, common maidenhair, southern maiden-hair, southern maidenhair fern, Venus hair, Venus hair fern, Venus's-hair fern

rosy maidenhair, rough maidenhair



scales golden brown to medium brown, concolored, iridescent, margins entire or occasionally with single broad tooth near base.


scales dark reddish brown, concolored, margins entire.


lax-arching or pendent, closely spaced, 15–75 cm.

arching, clustered, 20–37 cm.


0.5–1.5 mm diam., glabrous, occasionally glaucous.

1–2 mm diam., adaxially hispid, not glaucous.


lanceolate, pinnate, 10–45 × 4–15 cm, glabrous, gradually reduced distally;

proximal pinnae 3(–4)-pinnate;

rachis straight to flexuous, glabrous, not glaucous.

lanceolate, pinnate or occasionally pseudopedate, 1-pinnate distally, 12–18 × 6.5–8 cm;

proximal pinnae 1–4-pinnate;

indument of light-colored, sparse, multicellular hairs;

rachis straight, densely hispid, not glaucous.

Ultimate segments

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 to long-triangular, ca. 2 times as long as broad, progressively reduced toward apex of penultimate divisions;

basiscopic margin oblique;

acroscopic margin of fertile segments crenulate, sterile segments sharply denticulate;

apex obtuse or acute.


transversely oblong or crescent-shaped, 1–3(–7) mm, glabrous.

False indusia

± round, 0.6–0.9 mm diam., covered with reddish brown, stiff, needlelike bristles.


mostly 40–50 µm diam. 2n = 120.

mostly 40–60 µm diam.


stalks 0.5–3.5 mm, dark color extending into segment base.

stalks 0.2–0.3 mm, dark color generally entering into segment base.

Adiantum capillus-veneris

Adiantum hispidulum

Phenology Sporulating spring–summer. Sporulating summer–fall.
Habitat Moist calcareous cliffs, banks, and ledges along streams and rivers, walls of lime sinks, canyon walls (in the American southwest), around foundations, on mortar of storm drains Banks and old walls
Elevation 0–2500 m (0–8200 ft) 0–100 m (0–300 ft)
from FNA
AL; AR; AZ; CA; CO; FL; GA; KY; LA; MO; MS; NC; NM; NV; OK; SC; SD; TN; TX; UT; VA; BC; Mexico; Central America; West Indies; South America in Venezuela; Peru; tropical to warm temperate regions in Eurasia and Africa
[WildflowerSearch map]
[BONAP county map]
from FNA
CT; GA; Asia in s India; e Africa; Pacific Islands [Introduced in North America]
[BONAP county map]

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 hispidulum is represented by sporadic escapes from cultivation in the flora, possibly naturalized locally. It also has been reported from Florida and Louisiana.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 2. FNA vol. 2.
Parent taxa Pteridaceae > Adiantum Pteridaceae > Adiantum
Sibling taxa
A. aleuticum, A. hispidulum, A. jordanii, A. melanoleucum, A. pedatum, A. tenerum, A. tricholepis, A. viridimontanum
A. aleuticum, A. capillus-veneris, A. jordanii, A. melanoleucum, A. pedatum, A. tenerum, A. tricholepis, A. viridimontanum
Synonyms A. capillus-veneris var. modestum, A. capillus-veneris var. protrusum, A. capillus-veneris var. rimicola
Name authority Linnaeus: Sp. Pl. 2: 1096. (1753) Swartz: J. Bot. (Schrader) 1800(2): 82. (1801)
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