Mountain Bladder Fern (Cystopteris montana)

Uses

Toxicity

Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.

Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable^[5]. 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^[4].

Root. An emergency food, it is only used when all else fails^[4].

Plant part: Root

Environment

Range

Northern, but not arctic, Europe, including Britain, east to Siberia. Also in northern N. America.

Habitat

Damp, usually basic, rocks on mountains, 700 - 1100 metres in Northern England and Scotland^[3].

Light

partial sun

Shade tolerance

permanent shade

Water

moderate

Hardiness

Zone 4+

Soil textures

sandy, loamy, clay

Soil pH

acid, neutral, alkaline

Drainage

well drained

Tolerates Nutritionally Poor Soil

Drought

intolerant

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^[2].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.

Cultivation

Prefers a shady position in a moist but well-drained soil, succeeding in most soil types^[5]. Plants can tolerate up to 4 hours direct sun per day^[5]. Prefers a pH between 6.5 and 7, but tolerates a range from 5.5 to 7.5^[5]. Prefers high humidity, plants die back early in dry seasons^[5]. Members of this genus are rarely if ever troubled by browsing deer^[6]. A very ornamental plant^[1]. Plants spread by means of a creeping rhizome^[1].

References

F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00

↩1 ↩2

Bird. R. (Editor) Growing from Seed. Volume 4. Thompson and Morgan. 1990-00-00

↩

Clapham, Tootin and Warburg. Flora of the British Isles. Cambridge University Press 1962-00-00

↩

Schofield. J. J. Discovering Wild Plants - Alaska, W. Canada and the Northwest.

↩1 ↩2

Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5

↩1 ↩2 ↩3 ↩4 ↩5

Thomas. G. S. Perennial Garden Plants J. M. Dent & Sons, London. 1990-00-00 ISBN 0 460 86048 8