Christmas Fern

Polystichum acrostichoides

Physical Characteristics

Polystichum acrostichoides is an evergreen Fern growing to 0.6 m (2ft) by 0.5 m (1ft 8in) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 4. It is in leaf all year. Suitable for: light (sandy) and medium (loamy) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) or semi-shade (light woodland). It prefers moist soil.

Distribution

Eastern N. America - Nova Scotia to Wisconsin, south to Florida, Texas and Mexico.

Habitats

Woodland Garden Dappled Shade; Shady Edge; not Deep Shade;

Edible Uses

Edible Parts: Leaves Edible Uses: Young fronds[159, 257]. No more details are given, but they are probably harvested as they unfurl and eaten cooked.

Medicinal Uses

Antiaphonic Emetic Poultice Christmas fern was employed medicinally by several native North American Indian tribes, who used it to treat a variety of complaints[257]. It is little, if at all, used in modern herbalism. A tea made from the root is blood purifier, emetic and febrifuge[222, 257]. It is used in the treatment of chills, fevers, pneumonia, stomach or bowel complaints and rheumatism[222, 257]. A poultice of the root is used in the treatment of rheumatism[222]. A decoction of the root has been massaged into rheumatic joints[257]. The powdered root has been inhaled and then coughed up in order to restore the voice[257].

Known Hazards

Although we have found no reports of toxicity for this species, a number of ferns contain carcinogens so some caution is advisable[200]. 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[172].