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Plants

Osmunda claytoniana

Interrupted Fern

a member of the Osmunda genus in the family Osmundaceae.

No photo available

Taxonomy and growth

Genus
Osmunda
Height
0.5 m
Spread
0.3 m

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.

This section contains historical Plants For A Future notes marked noncommercial.

Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable[7]. 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[3].

Edible uses

This section contains historical Plants For A Future notes marked noncommercial.

The young fronds are eaten[5]. Cooked as a vegetable[4][10]. The centre of the clump, below ground level, is the source of a small edible pith called 'fern butter'[5].

Plant part
Leaves
Plant part
Stem

Medicinal uses

Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.

This section contains historical Plants For A Future notes marked noncommercial.

The roots are used as an adulterant for Dryopteris felix-mas in the treatment of internal worms[9].

Product or use
Vermifuge

Environment

Range
E. Asia - China, Japan, Himalayas. Eastern N. America.
Habitat
Wet places in C. Japan[11]. Open slopes, rarely in forests, 2800 - 3300 metres in Kashmir[2].
Light
full sun
Shade tolerance
light shade
Water
high
Hardiness
Zone 3+
Soil textures
sandy, loamy, clay
Soil pH
very acid, acid, neutral, alkaline
Tolerates Nutritionally Poor Soil
No
Drought
intolerant

Propagation

This section contains historical Plants For A Future notes marked noncommercial.

Spores - they very quickly lose their viability (within 3 days) and are best sown as soon as they are ripe on the surface of a humus-rich sterilized soil in a lightly shaded place in a greenhouse. Keep the compost moist, preferably by putting a plastic bag over the pot. Plants develop very rapidly, 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. Cultivars usually come true to type[7]. Division of the rootstock in the dormant season. This is a very strenuous exercise due to the mass of wiry roots[7].

Cultivation

This section contains historical Plants For A Future notes marked noncommercial.

Likes a soil of swamp mud and loamy or fibrous peat, sand and loam[1]. Succeeds in most moist soils, preferring acid conditions[7]. Requires a constant supply of water, doing well by ponds, streams etc[1]. Plants thrive in full sun so long as there is no shortage of moisture in the soil and also in shady situations beneath shrubs etc[7]. Requires a shady position[6]. Plants are hardy to at least -20°c, they are evergreen in warm winter areas but deciduous elsewhere[7]. Members of this genus are rarely if ever troubled by browsing deer[8]. A very ornamental plant[1].

References

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

    ↩1↩2↩3

  2. Singh. Dr. G. and Kachroo. Prof. Dr. P. Forest Flora of Srinagar. Bishen Singh Mahendra Pal Singh 1976-00-00

    ↩

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

    ↩

  4. Kunkel. G. Plants for Human Consumption. Koeltz Scientific Books 1984-00-00 ISBN 3874292169

    ↩

  5. Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9

    ↩1↩2

  6. Brickell. C. The RHS Gardener's Encyclopedia of Plants and Flowers Dorling Kindersley Publishers Ltd. 1990-00-00 ISBN 0-86318-386-7

    ↩

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

    ↩1↩2↩3↩4↩5↩6

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

    ↩

  9. Chopra. R. N., Nayar. S. L. and Chopra. I. C. Glossary of Indian Medicinal Plants (Including the Supplement). Council of Scientific and Industrial Research, New Delhi. 1986-00-00

    ↩

  10. Manandhar. N. P. Plants and People of Nepal Timber Press. Oregon. 2002-00-00 ISBN 0-88192-527-6

    ↩

  11. Ohwi. G. Flora of Japan. (English translation) Smithsonian Institution 1965-00-00

    ↩

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