Marsh Fern, Eastern marsh fern
Thelypteris palustris

Family: Thelypteridaceae

What it is like

Thelypteris palustris is a deciduous Fern growing to 0.8 m (2ft 7in) by 0.6 m (2ft) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 4. The seeds ripen from July to August. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid and neutral soils and can grow in very acid soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Height (m): 0.8

Where it is found

Marshes and fens, often abundant in carr or alder wood.

Europe, incl Britain, from Norway south and east to Spain, temperate Asia to China, E. N. America.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 1

Edible young fern. The part that is eaten is not specified, it is likely to be the young leaves as they unfurl in spring and early summer.

Medicine

Rating: 1

The roots have been used in the treatment of women's complaints.

Women's complaints: A very vague title, it deals with a miscellany of problems peculiar to the female sex.

Other

Rating:

How it is grown

Thrives in sun or shade in almost any soil with a pH between 5 and 7. Grows well by water and in wet woods. A very hardy plant, tolerating temperatures down to about -30°c. Members of this genus are rarely if ever troubled by browsing deer. Plants have a wandering root system and can be invasive.

Propagating it: Spores - best sown as soon as they are ripe, though they can also be sown in the spring. Sow them 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. This is best done in the spring.

Best place to grow: Woodland Garden Sunny Edge; Dappled Shade; Shady Edge; Bog Garden;

Habit: Fern

Hardiness: 4-8

Growth: Fast

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist, wet

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

Dryopteris thelypteris. Lastrea thelypteris. (L.)Bory.