Adiantum capillus-veneris |
Adiantum pedatum |
|
---|---|---|
black maidenhair fern, common maidenhair, southern maiden-hair, southern maidenhair fern, Venus hair, Venus hair fern, Venus's-hair fern |
adiante du Canada, five-fingered fern, northern maidenhair, northern maidenhair fern |
|
Stems | short-creeping; scales golden brown to medium brown, concolored, iridescent, margins entire or occasionally with single broad tooth near base. |
short-creeping; scales bronzy deep yellow, concolored, margins entire. |
Leaves | lax-arching or pendent, closely spaced, 15–75 cm. |
lax-arching (rarely pendent), closely spaced, 40–75 cm. |
Petiole | 0.5–1.5 mm diam., glabrous, occasionally glaucous. |
1–2 mm diam., glabrous, occasionally glaucous. |
Blade | 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, pseudopedate, 1-pinnate distally, 15–30 × 15–35 cm, glabrous; proximal pinnae 3–9-pinnate; rachis straight, glabrous, occasionally 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, ca. 3 times as long as broad; basiscopic margin straight; acroscopic margin lobed, lobes separated by narrow incisions 0–0.9(–1.1) mm wide; apex obtuse, divided into shallow, rounded lobes separated by shallow sinuses 0.1–2(–3.7) mm deep, margins of lobes crenulate or crenate-denticulate. |
Indusia | transversely oblong or crescent-shaped, 1–3(–7) mm, glabrous. |
transversely oblong, 1–3 mm, glabrous. |
Spores | mostly 40–50 µm diam. 2n = 120. |
mostly 34–40 µm diam. 2n = 58. |
Segment | stalks 0.5–3.5 mm, dark color extending into segment base. |
stalks 0.5–1.5(–1.7) mm, dark color entering into segment base. |
Adiantum capillus-veneris |
Adiantum pedatum |
|
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 | Rich, deciduous woodlands, often on humus-covered talus slopes and moist lime soils |
Elevation | 0–2500 m (0–8200 ft) | 0–700 m (0–2300 ft) |
Distribution |
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
|
AL; AR; CT; DC; DE; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; VA; VT; WI; WV; NB; NS; ON; QC
|
Discussion | 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.) |
Once considered a single species across its range in North America and eastern Asia, Adiantum pedatum is considered to be a complex of at least three vicariant species (A. pedatum and A. aleuticum occur in North America) and a derivative allopolyploid species (C. A. Paris 1991). Adiantum pedatum in the strict sense is restricted to deciduous woodlands in eastern North America. (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 | ||
Synonyms | A. capillus-veneris var. modestum, A. capillus-veneris var. protrusum, A. capillus-veneris var. rimicola | A. pedatum, A. pedatum |
Name authority | Linnaeus: Sp. Pl. 2: 1096. (1753) | Linnaeus: Sp. Pl. 2: 1095. (1753) |
Web links |
|