Adder's tongue fern

Ophioglossum reticulatum

Physical Characteristics

Ophioglossum reticulatum is a deciduous Fern growing to 0.2 m (0ft 8in) by 0.1 m (0ft 4in) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 10. The plant is self-fertile. Suitable for: light (sandy) and medium (loamy) soils. Suitable pH: mildly acid and neutral soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Distribution

Pantropical.

Habitats

Edible Uses

Edible Parts: Leaves Edible Uses: Young fronds are commonly eaten as a salad or vegetable[332 ]. A sweet flavour[46 ]. The leaves should be blanched only; if boiled too much they turn into slime[299 ].

Medicinal Uses

Antiinflammatory Skin A warm decoction of the rhizome is used topically on boils[299 ]. The leaf juice is drunk against spasms of the heart[299 ]. The leaves, boiled in oil, are applied to wounds[299 ]. The plant is used as an anti-inflammatory medicine[299 ].

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 ].