Common Name: Mountain Bladder Fern

General Information

Cystopteris montana is a deciduous fern with creeping stems; it forms a slowly spreading clump usually around 15 - 40cm tall and 20cm or more wide.
The plant is sometimes harvested from the wild for use as an emergency food. The plant is sometimes grown as an ornamental.

Known Hazards

Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable[].
Many ferns also contain thiaminase, an enzyme that robs the body of its vitamin B complex. In small quantities this enzyme will do no harm to people eating an adequate diet that is rich in vitamin B, though large quantities can cause severe health problems. The enzyme is destroyed by heat or thorough drying, so cooking the plant will remove the thiaminase[].

Botanical References

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Range

Widespread through the northern temperate zones of America and Eurasia, extending to the subarctic

Habitat

Damp, usually basic, rocks on mountains, 700 - 1100 metres in Northern England and Scotland[]. Terrestrial, growing in wet woods or along water courses; at elevations from near sea level to 3,500 metres[].

Properties

Edibility Rating
Habit	Deciduous Fern
Height	0.25 m
Cultivation Status	Ornamental, Wild

Cultivation Details

Cystopteris montana is very widely spread through the temperate zone, can be found at elevations up to 3,500 metres. A very cold-tolerant plant, when fully dormant it can withstand temperatures down to around -30°c[].
Prefers a shady position in a moist but well-drained soil, succeeding in most soil types[]. Plants can tolerate up to 4 hours direct sun per day[]. Prefers a pH between 6.5 and 7, but tolerates a range from 5.5 to 7.5[].
Prefers high humidity, plants die back early in dry seasons[].
Members of this genus are rarely if ever troubled by browsing deer[].
A very ornamental plant[]. Plants spread by means of a creeping rhizome[].

Edible Uses

Root. An emergency food, it is only used when all else fails[].

Medicinal

None known

Other Uses

None known

Propagation

Spores - best sown as soon as ripe on the surface of a humus-rich sterilized soil. Keep the compost moist, preferably by putting a plastic bag over the pot. Germinates in 1 - 3 months at 20°c[].Pot on small clumps of plantlets as soon as they are large enough to handle and keep humid until they are well established. Do not plant outside until the ferns are at least 2 years old.
Division in spring.