Sparganium hyperboreum, Laest. ex Beurl.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1980, Flora Europaea. Volume 5. Alismataceae to Orchidaceae (Monocotyledones), Cambridge: Cambridge University Press : 275

7. S. hyperboreum Laest. ex Beurl. , Öfters. Kongl. Vet.-Akad. Förhandl. 9: 192 (1853).

Stem up to 30 cm, floating, with not more than 5 internodes. Leaves elliptical in transverse section, rather thick, not translucent. Inflorescence simple. Lowest bract distinctly longer than inflorescence. Female capitula 2-3(-4), irregularly disposed, the lower mostly pedunculate and remote, the upper sessile and crowded. Male capitulum remote from the female, solitary (rarely 2 and then close together and appearing as one). Fruit broadly obovoid, pale brownish-yellow, shortly pedicellate; style minute or absent. 2n =3O. Fennoscandia and N. Russia; one station in S. Alps. Fe Is It No Rs (N) Su.