Crispa means finely waved, or curled.
Rhizome: short-creeping, branching, covered with old stipe bases, scales thin, pale brown.
Frond: 30 cm high by 8 cm wide, deciduous, dimorphic, the sterile fronds half the length (to 15 cm) of the fertile ones, blade/stipe ratio: 1:2.
Stipe: straw-colored near the base, scaly at the base, vascular bundles: 2.
Blade: 3-pinnate with reports of more division, deltate to ovate, herbaceous, bright green, glabrous.
Pinnae: 4 to 6 pair, lanceolate, 2-4 cm, the fertile ones contracted; margins toothed; veins free.
Sori: scattered along veins, submarginal, indusium: false, strongly enrolled, sporangia: yellow, maturity: midsummer.
Habitat: among acidic rocks in areas with late-lying snow.
Distribution: Europe, at higher altitudes or latitudes.
Hardy to -40°C, USDA Zone 2.
The common name is well-chosen. This is near C. acrostichoides, but more divided and deciduous.
Osmunda crispa L.
Allosorus crispus (L.) Röhling