Polypodium lineare

Family: Polypodiaceae

What it is like

Polypodium lineare is an evergreen Fern growing to 0.2 m (0ft 10in). It is in leaf all year. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. 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): 0.3

Where it is found

Epiphytic on tree trunks and rocks in lowland and low mountains all over Japan. Often found on old brick walls.

E. Asia - China, Japan, Korea.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 0

Medicine

Rating: 1

The whole plant is antiphlogistic and diuretic. It is used in the treatment of urinary calculus, urinary tract infections, bacterial dysentery, chronic bronchitis and rheumatism.

Antiphlogistic: Reduces inflammation.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.

Urinary: Treats urinary problems, including urinary tract infection (UTI).

Other

Rating:

How it is grown

We have very little information on this species and do not know if it will be hardy in Britain, though judging by its native range it should succeed outdoors in many parts of this country. The following notes are based on the general needs of the genus. 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.

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:

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.

Its other names

Local names

Synonyms

Lepisorus thunbergiana. Pleopeltis elongata. non Kaulf. P. lepisorus. P. thunbergiana. Kaulf.