Cystopteris fragilis
bladder fern, brittle fern, fragile fern

Distribution: Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across the northern half of North America to the Atlantic Coast; circumboreal.

Habitat: Moist to moderately dry, often rocky places, lowlands to above timberline

Spores: April-September

Origin: Native

Growth Duration: Perennial

Conservation Status: Not of concern


Perennial with creeping stems and short internodes, not hairy, beset with old petiole bases; scales tan to light brown, lanceolate.


Leaves monomorphic, to 40 cm, clustered at apex of stem; petiole dark at base, becoming mostly green to pale yellow distally, shorter than or almost equal to blade, base scarcely scaley; blade lanceolate to narrowly elliptic, 1- or rarely 2-pinnate-pinnafitid, widest at or just below mid-stem, apex acute; gland-tipped hairs absent from rachis, costae, and pinnae axils; pinnae typically perpendicular to rachis, not curving, margins serrate to sharply toothed, pinnae nearest base pinnafitid to pinnate-pinnafitid, more or less even, basiscopic pinnules not enlarged, basal basiscopic pinnules sessile with a base truncate to obtuse, distal pinnae deltate to ovate; veins directed mostly into teeth.


Indusia ovate to lanceolate, gland-tipped hairs absent; spores spiny or verrucose, usually 39-60 micrometers.

Accepted Name:
Cystopteris fragilis (L.) Bernh.
Publication: Neues J. Bot. 1(2): 26, plate 2, fig. 9. 1806.

Synonyms & Misapplications:
Cystopteris dickieana Sim
Polypodium fragile L.
Additional Resources:

PNW Herbaria: Specimen records of Cystopteris fragilis in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Cystopteris fragilis checklist entry.

OregonFlora: Cystopteris fragilis information.

E-Flora BC: Cystopteris fragilis atlas page.

CalPhotos: Cystopteris fragilis photos.

USDA Plants: Cystopteris fragilis information.

32 photographs:
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