Common Name: Rattlesnake Fern

General Information

Botrychium virginianum is a perennial fern growing from a short, erect, fleshy rhizome with many fleshy roots. It produces a single frond each year, usually 25 - 70cm tall[].
The plant is harvested from the wild for local use as a food and a medicine. It is grown as an ornamental in gardens.

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

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Range

Temperate regions of northern and montane Europe, northeast Asia. N. America, through the tropics of C. America to Colombia, Venezuela, Ecuador, Peru

Habitat

Wet forests and wooded slopes, 900 - 3,800 metres in Guatemala[]. Rich moist or dry woods[]. Common to abundant, especially in shaded forests and shrubby second growth, rare or absent in arid regions from sea level to 1.500 metres[].

Properties

Edibility Rating
Medicinal Rating
Habit	Evergreen Fern
Height	0.40 m
Cultivation Status	Ornamental, Wild

Cultivation Details

Botrychium virginianum is a plant mainly found in the temperate zone, but also found in subtropical and tropical areas through central America to S. America.
Prefers a sandy loam with just a small portion of peat[]. Requires sharp drainage[]. Best grown in an open position[]. Plants can be difficult to establish.
The prothalli (young plants formed when the spores germinate) of this plant form a symbiotic relationship with a mycorrhizal fungus, similar to the association of orchid seedlings with an invading fungus[].
Unlike most species of ferns, the fronds of this species grow up straight and not curled inward, crozier fashion[].
Members of this genus are rarely if ever troubled by browsing deer[].

Edible Uses

This large succulent fern is boiled and eaten in the Himalayas[]. The report does not say which part of the plant is used, though it is probably the root[].

Medicinal

A poultice or lotion made from the roots is applied to snakebites, bruises, cuts and sores[, ].
A tea made from the roots is emetic, induces sweating and is expectorant[]. It is used in the treatment of lung ailments[, ].

Other Uses

None known

Propagation

Spores - best surface sown as soon as they are ripe in a greenhouse and do not allow the compost to dry out. Placing the pot in a plastic bag helps to maintain a humid atmosphere which promotes germination and growth. Prick out small clumps into pots when they are large enough to handle and keep moist until established. Grow on in a greenhouse for at least the first winter and plant out in late spring.
Division. It is best not to try and disturb this plant[].