[citation needed] It consists of a two-part frond, separated into a 4-12 cm rounded diamond-shaped leaf sheath and narrow branchless spore-bearing spike.

[4] Linnaeus described adder's-tongue with the binomial Ophioglossum vulgatum in his Species Plantarum of 1753.

[2][6] This small, hard-to-spot plant can occur singly in unimproved pastures, rock crevices and grassy path-sides, but also can occur in colonies of hundreds of plants in sand dunes.

Finland has fitting lime rich soil habitat sparsely, but the plant has found an equivalent living habitat from Finland's seashores affected by a post-glacial rebound: land just risen from the sea is often quite neutral and cointains mineral salts in addition to being open and bare enough.

A tea made from the leaves was used as a traditional European folk remedy for internal bleeding and vomiting.