Licorice Fern
Polypodium glycyrrhiza
Family: Polypodiaceae
What it is like
Polypodium glycyrrhiza is a FERN growing to 0.5 m (1ft 8in) by 0.5 m (1ft 8in). See above for USDA hardiness. It is hardy to UK zone 7. The seeds ripen from November to March. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil and can tolerate drought.
Height (m): 0.5
Where it is found
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.
Western N. America - Alaska to California.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
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.
Root: includes bulbs, corms, tubers, rhizomes etc.
Medicine
Rating: 2
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.
Alterative: Causes a gradual beneficial change in the body, usually through improved nutrition and elimination, without having any marked specific action.
Carminative: Reduces flatulence and expels gas from the intestines.
Haemostatic: Controls internal bleeding.
Pectoral: Relieves respiratory diseases, a remedy for chest diseases.
Other
Rating:
Food Forest: Plants for Edible Forest Gardens and Food Forests.
How it is grown
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. For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. An evergreen. The plant growth habit is a clumper with limited spread. The root pattern is rhizomatous with underground stems sending roots and shoots along their length.
Propagating it: 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.
Best place to grow: Woodland Garden Dappled Shade; Shady Edge; North Wall. In. East Wall. In.
Habit: Fern
Hardiness: 6-9
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-shade, no shade
Moisture: Moist
Things to keep in mind
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.