Athyrium distentifolium var. americanum
Gerald D. Carr

Flora of Oregon

Petioles 10–30 cm long.

Blade segments deeply divided, lanceolate to narrowly elliptic, 10–60 × 5–25 cm; rachis and costae with sparse pale brown scales, glands absent.

Pinnae with a distinct stalk, narrowly triangular; acroscopic lobe scarcely enlarged.

Sori round, borne on veins near the margins of the pinnules.

Indusia absent or minute; pinnule teeth cupping the sorus on 1 side.

Wet montane meadows, rocky hillsides, talus slopes. 1000– 3000 m. BR, BW, Casc, ECas, Owy. CA, ID, NV, WA; north to British Columbia, disjunct populations in Yukon, Quebec, Newfoundland, and Greenland. Native.

Flora of North America

as described under Athyrium alpestre

Varieties ca. 3 (1 in the flora): North America, Europe, Asia.

Photo images

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Herbarium specimens

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