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Wright's cliffbrake

pelléade glabre, simple cliff-brake, slender cliff-brake, smooth cliff-brake, smooth cliffbrake fern

Stems

compact, ascending, stout, 5–10 mm diam.;

scales bicolored, linear-subulate, 0.1–0.3 mm wide, centers black, thick, margins brown, thin, erose-dentate.

compact, ascending, stout, 5–10 mm diam.;

scales uniformly reddish brown, linear-subulate, 0.1–0.3 mm wide, thin, margins sinuous, entire to denticulate.

Leaves

monomorphic, clustered on stem, 6–40 cm;

croziers sparsely villous.

monomorphic, clustered on stem, 2–40 cm;

croziers sparsely villous.

Petiole

dark brown, lustrous, flattened or slightly grooved adaxially, without prominent articulation lines.

brown, lustrous, rounded adaxially, occasionally with prominent articulation lines near base.

Blade

linear-oblong, 2-pinnate proximally, 1.5–5 cm wide;

rachis brown throughout, straight, shallowly grooved adaxially, usually glabrous.

linear-oblong to ovate-lanceolate, 1–2-pinnate proximally, 1–8 cm wide;

rachis brown throughout, straight, rounded adaxially, nearly glabrous.

Ultimate segments

narrowly oblong, 5–20 mm, leathery, glabrous;

margins recurved on fertile segments, usually covering less than 1/2 abaxial surface, borders whitish, crenulate;

apex mucronate.

oblong-lanceolate, 5–20 mm, leathery to herbaceous, glabrous except for occasional hairlike scales abaxially near midrib;

margins recurved on fertile segments, covering less than 1/2 abaxial surface, borders whitish, erose-denticulate;

apex obtuse.

Pinnae

perpendicular to rachis or slightly ascending, not decurrent on rachis, usually with 3–9 ultimate segments;

costae straight, 2–20 mm, usually shorter than ultimate segments.

somewhat ascending, decurrent on rachis, usually with 3–7 lobes or ultimate segments;

costae when present straight, 1–50 mm, often shorter than ultimate segments.

Veins

of ultimate segments obscure.

of ultimate segments usually obscure.

Sporangia

long-stalked, containing 64 spores, intermixed with sparse farina-producing glands.

long-stalked, containing 32 or 64 spores, not intermixed with farina-producing glands.

2n

= 116.

Pellaea wrightiana

Pellaea glabella

Phenology Sporulating summer–fall.
Habitat Cliffs and rocky slopes, on a variety of acidic to mildly basic substrates
Elevation 300–2900 m (1000–9500 ft)
Distribution
from FNA
AZ; CO; NC; NM; OK; TX; UT; n Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
AR; AZ; CO; CT; IA; ID; IL; IN; KS; KY; MA; MD; MI; MN; MO; MT; ND; NE; NM; NY; OH; OK; PA; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; ON; QC; SK; only in the flora
[WildflowerSearch map]
[BONAP county map]
Discussion

W. H. Wagner Jr. (1965) suggested that Pellaea wrightiana was a fertile allotetraploid hybrid between P. truncata (as P. longimucronata) and P. ternifolia. This hypothesis has been confirmed by isozyme analyses (M. D. Windham 1988). Pellaea wrightiana is therefore treated as a distinct species rather than a variety of P. ternifolia. This tetraploid species hybridizes with P. truncata and P. ternifolia subsp. arizonica to produce sterile triploids and tetraploids with intermediate morphology and malformed spores. Pellaea wrightiana has also hybridized with P. atropurpurea to form a rare apogamous pentaploid known only from western Oklahoma.

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

Pellaea glabella includes four geographically and genetically isolated taxa treated here as subspecies. D. B. Lellinger (1985) recognized three species in this difficult group, but isozyme analyses (G. J. Gastony 1988) showed that one of these (P. suksdorfiana) is an autotetraploid derivative of the diploid known as P. occidentalis. As a result, Gastony recognized just two species: P. glabella (with two varieties) and P. occidentalis (with two subspecies). The few morphologic features that distinguish these taxa, however, are subtle and environmentally plastic, and the isozyme data indicate that they are less divergent genetically than any other pair of Pellaea species in North America. Therefore, a more conservative taxonomic treatment seems warranted.

Subspecies 4.

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

Key
1. Sporangia containing 32 spores; spores averaging 60-72 µm diam.
→ 2
1. Sporangia containing 64 spores; spores averaging 38-52 µm diam.
→ 3
2. Some ultimate segments (especially terminal segments) with hairlike scales abaxially near midrib; e North America (with outlying station in Texas panhandle).
subsp. glabella
2. Ultimate segments essentially glabrous; w North America.
subsp. simplex
3. Ultimate segments (especially terminal segments) with hairlike scales abaxially near midrib; Missouri.
subsp. missouriensis
3. Ultimate segments glabrous; w North America.
subsp. occidentalis
Source FNA vol. 2. FNA vol. 2.
Parent taxa Pteridaceae > Pellaea Pteridaceae > Pellaea
Sibling taxa
P. andromedifolia, P. atropurpurea, P. brachyptera, P. breweri, P. bridgesii, P. cordifolia, P. gastonyi, P. glabella, P. intermedia, P. lyngholmii, P. mucronata, P. ovata, P. ternifolia, P. truncata
P. andromedifolia, P. atropurpurea, P. brachyptera, P. breweri, P. bridgesii, P. cordifolia, P. gastonyi, P. intermedia, P. lyngholmii, P. mucronata, P. ovata, P. ternifolia, P. truncata, P. wrightiana
Subordinate taxa
P. glabella subsp. glabella, P. glabella subsp. missouriensis, P. glabella subsp. occidentalis, P. glabella subsp. simplex
Synonyms P. ternifolia var. wrightiana
Name authority Hooker: Sp. Fil. 2: 142. (1858) Mettenius ex Kuhn: Linnaea 36: 87. (1869)
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