Botanical Name: Dryopteris marginalis
Species: D. marginalis
Common Names: Marginal shield fern or Marginal wood fern, Leather Wood Fern
Dryopteris marginalis is native to N. America – Canada to Georgia and westwards to the Rockies. It grows on the
damp woods and swamps. Rocky, wooded slopes and ravines, edges of woods, stream banks and roadbanks, and rock walls at elevations of 50 – 1500 metres.
Dryopteris marginalis is an evergreen fern throughout its range, along with Christmas fern (Polystichum acrostichoides) it is one of the few evergreen ferns. Marginal wood fern grows from a clump with a prominent central rootstock, this rootstock may be exposed and give this fern the appearance of being like a small tree fern. Often, the dead leaves will accumulate beneath the plant. The stipe, or stem which supports the leaf is approximately 1/4 the length of the leaf and covered in bright golden brown scales. The stipe itself is grooved on the upward-facing side and dark red-brown at the base and becoming green further up the leaf.
The leaf is a dark blue-green and thick and leathery in texture. It grows 1–2 ft in height and approximately 6 in wide. Each leaf is broken up into leaflets which are arranged on either side of the main stalk. The tips of these leaflets are generally curved toward the tip of the leaf. These leaflets themselves are divided into subleaflets which are blunt-tipped and either serrated or lobed. The fertile leaflets (leaflets bearing sori and spores) are similar to the fertile leaflets in size and appearance. The round sori are located on the margins of the leaf tissue. Before the sori are ripe they start gray then they turn an interesting blue-violet color before finally turning brown when they are mature. The sori are covered in a kidney-shaped indusium which is smooth.
Prefers an acid to neutral soil, succeeding in ordinary fertile soil in a shady position. Succeeds in full sun but grows best in a shady position with only 2 – 3 hours sun per day. Tolerates a pH range from 4.5 to 7. Dislikes heavy clay. Prefers a good supply of water at its roots but succeeds in dry shade and tolerates drought when it is established. A very hardy plant, tolerating temperatures down to about -30°c. Members of this genus are rarely if ever troubled by browsing deer. Hybridizes in the wild with several other species. Special Features: Attractive foliage, North American native, Wetlands plant, There are no flowers or blooms. The plant is heat tolerant in zones 8 through 1. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of “heat days” experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) 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
Through spores – can be sown at any time of the year in a greenhouse. Surface sow on a sterilised compost and keep moist, possibly by placing the pot in a plastic bag. Germinates in 1 – 3 months at 20°c. Pot up small clumps of the plants when they are large enough to handle and grow on in a shady part of the greenhouse until large enough to plant out. Division in spring. Larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.
Edible Uses: Not known to us.
The root contains ‘filicin’, a substance that paralyses tapeworms and other internal parasites and has been used as a worm expellent. It is one of the most effective treatments known for tapeworms – its use should be immediately followed by a non-oily purgative such as magnesium sulphate in order to expel the worms from the body. An oily purge, such as caster oil, increases the absorption of the fern root and can be dangerous. The root is harvested in the autumn and can be dried for later use, it should not be stored for longer than 12 months. This remedy should be used with caution and only under the supervision of a qualified practitioner. The root is toxic and the dosage is critical. See also the notes above on toxicity. An infusion of the root has been used in the treatment of rheumatism. A warm infusion, held in the mouth, has been used to treat toothaches.
Landscape Uses:Container, Ground cover, Specimen, Woodland garden.
Known Hazards: Although we have found no reports for this species, a number of ferns contain carcinogens so some caution is advisable. The fresh plant contains 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. However, there have been reports for other species of ferns suggesting that even cooked fronds can have a long term harmful effect. Some caution is therefore advised.
Disclaimer : The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplement, it is always advisable to consult with your own health care provider.