Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Adiantum capillus-veneris

Adiantum viridimontanum

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

Green Mountain maidenhair, Green Mountain 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.

arching to stiffly erect, often densely clustered, 38–75(–90) cm.
Petiole

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

1–3 mm diam., glabrous, often 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 to funnel-shaped, pseudopedate, 1-pinnate distally, 10–35 × 10–35(–45) cm, glabrous;

proximal pinnae 2–7-pinnate;

rachis straight, glabrous, often 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.

long-triangular, ca. 2.5 times as long as broad;

basiscopic margin oblique;

acroscopic margin lobed, lobes separated by narrow (less than 1 mm) incisions;

apex acute, usually entire.
Indusia

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

False indusia

transversely oblong, mostly 2–5(–10) mm, glabrous.
Spores

mostly 40–50 µm diam. 2n = 120.

mostly 45–58 µm diam. 2n = 116.
Segment

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

stalks (0.4–)0.6–1.5(–1.9) mm, dark color commonly entering into segment base.

Adiantum capillus-veneris

Adiantum viridimontanum
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 Restricted to serpentine sites where it occurs in rock clefts, on talus slopes, and in well-developed serpentine soils
Elevation 0–2500 m (0–8200 ft) 200–800 m (700–2600 ft)
Distribution
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
VT
[BONAP county map]
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.)

Adiantum viridimontanum, an allopolyploid from a sterile hybrid between A. pedatum and A. aleuticum, is known only from north central Vermont (C. A. Paris and M. D. Windham 1988). Additional populations may eventually be located on serpentine in southern Quebec.

(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. hispidulum, A. jordanii, A. melanoleucum, A. pedatum, A. tenerum, A. tricholepis
Synonyms A. capillus-veneris var. modestum, A. capillus-veneris var. protrusum, A. capillus-veneris var. rimicola
Name authority Linnaeus: Sp. Pl. 2: 1096. (1753) Paris: Rhodora 93: 108. (1991)
Web links 
see all taxa on an iNaturalist map
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America

The species comparison tool is brought to you by:
Northwest Wildflowers