Practical
Plants

Polypodium glycyrrhiza

Licorice Fern

a member of the Polypodium genus in the family Polypodiaceae.

No photo available

Taxonomy and growth

Height
0.45 m
Spread
0.45 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[3]. 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[1].

Edible uses

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

Root - raw or cooked[7] The root is sweetly liquorice-flavoured but is thin and fibrous and virtually inedible[3]. The root was commonly chewed for its very pleasant flavour by many native North American Indian tribes[6][7]. It was often used as an appetiser, especially for children who would not eat[6]. Apart from its used as a pleasantly flavoured chew, it was seen as a famine food and was only used when there was a shortage of better foods[2][7].

Plant part
Root

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.

Liquorice fern was employed medicinally by several native North American Indian tribes who used it especially as a treatment for a variety of chest complaints[7]. It is little, if at all, used in modern herbalism. The rhizomes are alterative, carminative, haemostatic and pectoral[7]. The raw rhizomes have been eaten, or an infusion has been used, in the treatment of coughs and colds, chest pains, shortness of breath and VD[7]. The roots have been chewed, and the juice swallowed, as a treatment for sore throats and the spitting or vomiting of blood[7]. A tea of the pounded boiled rhizomes, mixed with fir needles, has been used to treat measles[4]. Coughs have been treated by chewing and slowly swallowing the juice of the roasted rhizome[4]. The roots have been used in the treatment of colds and sore throats[6].

Product or use
Alterative
Product or use
Carminative
Product or use
Haemostatic
Product or use
Pectoral

Environment

Range
Western N. America - Alaska to California.
Habitat
Rocks, mossy tree trunks, logs etc, below 600 metres in coniferous and mixed forests in California[9]. Cliffs and rocky slopes along coasts, often epiphytic, on a variety of substrates[8].
Light
full sun
Shade tolerance
light shade
Water
moderate
Hardiness
Zone 7+
Soil textures
sandy, loamy, clay
Soil pH
acid, neutral, alkaline
Tolerances
drought
Tolerates Nutritionally Poor Soil
No
Drought
tolerant

Propagation

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

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. 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 and then only in a very well sheltered position. Division in spring[3].

Cultivation

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

Tolerates short periods of drought and direct sunlight, but it prefers bright filtered light[3]. Plants can be grown on a drystone wall[3]. Members of this genus are rarely if ever troubled by browsing deer[5]. There are several named varieties selected for their ornamental value[3]. Polypodium glycyrrhiza hybridizes with P. calirhiza and with P. hesperium to produce sterile triploids with misshapen spores[8].

References

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

    ↩

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

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  3. 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

  4. Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books 1980-00-00 ISBN 0-449-90589-6

    ↩1↩2

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

    ↩

  6. Turner. N. J. Food Plants of Coastal First Peoples UBC Press. Vancouver. 1995-00-00 ISBN 0-7748-0533-1

    ↩1↩2↩3

  7. Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998-00-00 ISBN 0-88192-453-9

    ↩1↩2↩3↩4↩5↩6↩7

  8. Flora of N. America http://flora.huh.harvard.edu/fna/

    ↩1↩2

  9. Munz. A California Flora. University of California Press 1959-00-00

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