The Temperate Database is in the process of being updated, with new records being added and old ones being checked and brought up to date where necessary. This record has not yet been checked and updated.

Common Name: Licorice Fern

General Information

Polypodium glycyrrhiza is a Fern up to 0.45 metres tall.
It is harvested from the wild for local use as a food and medicine

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

, ,

Range

Western N. America - Alaska to California.

Habitat

Rocks, mossy tree trunks, logs etc, below 600 metres in coniferous and mixed forests in California[]. Cliffs and rocky slopes along coasts, often epiphytic, on a variety of substrates[].

Properties

Edibility Rating
Medicinal Rating
Habit	Fern
Height	0.45 m
Cultivation Status	Wild

Cultivation Details

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

Edible Uses

Root - raw or cooked[] The root is sweetly liquorice-flavoured but is thin and fibrous and virtually inedible[]. The root was commonly chewed for its very pleasant flavour by many native North American Indian tribes[, ]. It was often used as an appetiser, especially for children who would not eat[]. 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[, ].

Medicinal

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[]. It is little, if at all, used in modern herbalism.
The rhizomes are alterative, carminative, haemostatic and pectoral[]. 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[]. The roots have been chewed, and the juice swallowed, as a treatment for sore throats and the spitting or vomiting of blood[]. A tea of the pounded boiled rhizomes, mixed with fir needles, has been used to treat measles[].
Coughs have been treated by chewing and slowly swallowing the juice of the roasted rhizome[].
The roots have been used in the treatment of colds and sore throats[].

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. 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[].