About Cystopteris protrusa (Weath.) Blasdell
Unlike most other species in the genus Cystopteris, Cystopteris protrusa is strictly a terrestrial fern, and it often grows into large, dense colonies. It is also primarily a spring ephemeral. While a small number of fronds may still be present by late summer, most fronds have disappeared by this time. Its specific epithet, protrusa, comes from the characteristic that its rhizome extends a short distance past the current year's fronds to form the next year's leaf buds. This protruding growth is a reliable identifying feature for the species when observed in the field. The fern produces round sori, each covered by a bladder-shaped indusium.
