Cystopteris protrusa

Species Native to Missouri
Common Name: lowland fragile fern 
Type: Fern
Family: Cystopteridaceae
Native Range: North America
Zone: 2 to 9
Height: 0.50 to 1.50 feet
Spread: 0.50 to 1.50 feet
Bloom Time: Non-flowering
Bloom Description: Non-flowering
Sun: Part shade to full shade
Water: Medium
Maintenance: Low
Tolerate: Rabbit


Easily grown in loose, organically rich, medium moisture, well-drained soils in part shade to full shade. Add lime to acidic soils.

Noteworthy Characteristics

Cystopteris protrusa, commonly called fragile fern, is a small, somewhat airy, deciduous, Missouri native fern which occurs in rich woods, slopes, valleys and along streams throughout the State. Typically grows 6-15" tall. Features finely cut, bi-pinnate to tri-pinnate, erect to arching fronds. Fronds have brittle stipes (central stems) which easily break, hence the common name. A rhizomatous plant which emerges in very early spring and produces new fronds throughout the spring and summer. Very similar in appearance to Woodsia obtusa.

Genus name comes from the Greek words kystis meaning a bladder and pteris a fern.

Specific epithet means protruding.


No serious insect or disease problems.


Excellent for shaded areas of rock gardens. Also effective in woodland gardens, native plant gardens, shaded border fronts or on slopes or banks.