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rosy maidenhair, rough maidenhair

adiante des aléoutiennes, Aleutian maidenhair, five-finger fern, maidenhair fern, northern maiden-hair, northern maidenhair fern, western maidenhair, western maidenhair fern

Stems

short-creeping;

scales dark reddish brown, concolored, margins entire.

short-creeping or suberect;

scales bronzy deep yellow, concolored, margins entire.

Leaves

arching, clustered, 20–37 cm.

lax-arching to stiffly erect or pendent, often densely clustered, 15–110 cm.

Petiole

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

0.5–3 mm diam., glabrous, often glaucous.

Blade

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.

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.

Ultimate segments

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.

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.

False indusia

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

transversely oblong to crescent-shaped, 0.2–3.5(–6) mm, glabrous.

Spores

mostly 40–60 µm diam.

mostly 37–47 µm diam. 2n = 58.

Segment

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

stalks 0.2–0.9(–1.3) mm, dark color entering into segment base or not.

Adiantum hispidulum

Adiantum aleuticum

Phenology Sporulating summer–fall. Sporulating summer–fall.
Habitat Banks and old walls Wooded ravines, shaded banks, talus slopes, serpentine barrens, and coastal headlands (uncommon)
Elevation 0–100 m [0–300 ft] 0–3200 m [0–10500 ft]
Distribution
from FNA
CT; GA; Asia in s India; e Africa; Pacific Islands [Introduced in North America]
[BONAP county map]
from FNA
AK; AZ; CA; CO; ID; MD; ME; MT; NV; OR; PA; UT; VT; WA; WY; AB; BC; NF; QC; Mexico in Chihuahua
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

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.)

Source FNA vol. 2. Treatment author: Cathy A. Paris. FNA vol. 2. Treatment author: Cathy A. Paris.
Parent taxa Pteridaceae > Adiantum Pteridaceae > Adiantum
Sibling taxa
A. aleuticum, A. capillus-veneris, A. jordanii, A. melanoleucum, A. pedatum, A. tenerum, A. tricholepis, A. viridimontanum
A. capillus-veneris, A. hispidulum, A. jordanii, A. melanoleucum, A. pedatum, A. tenerum, A. tricholepis, A. viridimontanum
Synonyms A. pedatum var. aleuticum, A. boreale, A. pedatum subsp. aleuticum, A. pedatum subsp. calderi, A. pedatum subsp. subpumilum, A. pedatum var. subpumilum
Name authority Swartz: J. Bot. (Schrader) 1800(2): 82. (1801) (Ruprecht) Paris: Rhodora 93: 112. (1991)
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