Pellaea gastonyi Windham:
Canada (North America)
United States (North America)

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Unknown/Undetermined

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Global Range: Reported by Kartesz 1999 in Alberta, British Columbia, Saskatchewan, South Dakota, Wyoming, Manitoba and Missouri.

Pellaea gastonyi is an apogamous tetraploid that has originated through repeated hybridization between P . atropurpurea and P . glabella . Isozyme studies (G. J. Gastony 1988) indicate that P . glabella subsp. missouriensis was the diploid parent of plants found in Missouri, whereas diploid P . glabella subsp. occidentalis was involved in the origin of P . gastonyi populations occurring in western North America. Pellaea gastonyi is most often confused with P . atropurpurea , from which it differs in having sparsely villous rachises, smaller ultimate segments, and spores averaging more than 62 µm in diameter.

Stems compact, ascending, stout, 5--10 mm diam.; scales uniformly reddish brown, linear-subulate, 0.1--0.3 mm wide, thin, margins entire to denticulate. Leaves somewhat dimorphic, sterile leaves shorter than fertile leaves, clustered on stem, 8--25 cm; croziers villous. Petiole reddish purple to dark brown, lustrous, rounded adaxially, without prominent articulation lines. Blade elongate-deltate to lanceolate, 2-pinnate proximally, 3--6 cm wide; rachis purple or brown throughout, straight, rounded adaxially, sparsely villous with long, divergent hairs. Pinnae ascending or perpendicular to rachis, not decurrent on rachis or obscurely so, usually with 3--7 ultimate segments; costae straight, 2--30 mm, usually shorter than ultimate segments. Ultimate segments oblong-lanceolate, 7--30 mm, leathery, sparsely villous abaxially near midrib; margins usually recurved on fertile segments, covering less than 1/2 abaxial surface, borders whitish, crenulate; apex obtuse to slightly mucronate. Veins of ultimate segments obscure. Sporangia long-stalked, containing 32 spores, not intermixed with farina-producing glands.

Holotype for Pellaea gastonyi Windham
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): J. A. Calder & D. Savile
Year Collected: 1953
Locality: Kinbasket Mountain by Kinbasket River, northwest of Golden., British Columbia, Canada, North America
Microhabitat: Very common in rock crevices; rocky gullies and slopes at base of mountain.

Comments: Calcareous cliffs, crevices, and ledges; often dry, usually on limestone. Includes sites in the montane and subalpine zones. 100 - 1500 m.

Sporulating summer--fall. Calcareous cliffs and ledges, usually on limestone; 100--1500 m; Alta., B.C., Sask.; Mo., S.Dak., Wyo.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 21 - 80

Comments: Seventeen occurrences for Alberta and several other occurrences in Canada and the United States.

Canada

Rounded National Status Rank: N2 - Imperiled

United States

Rounded National Status Rank: NNR - Unranked

Rounded Global Status Rank: G2 - Imperiled

Reasons: The center of the range appears to be in Alberta and British Columbia, however, it also occurs in Saskatchewan and Manitoba, and several states in the United States. It is probably undercollected in British Columbia.

Environmental Specificity: Narrow. Specialist or community with key requirements common.

Comments: This species occurs on dry calcareous cliffs.

Global Short Term Trend: Unknown

Comments: In Alberta this species occurs Canmore Corridor and this area is impacted by residential development and limestone mining. The Columbia Valley in British Columbia is under development pressure and this may impact the species, however, otherwise secure and unthreatened in British Columbia. This species is known from one location in Manitoba, however, more probably exist. In Manitoba, resouce extraction is a potential threat.

Comments: Apogamous tetraploid, derived from repeated hybridization between Pellaea atropurpurea and Pellaea glabella; closely resembling P. atropurpurea, and probably underreported (FNA, 1993).