Empetrum nigrum, L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 14

1. E. nigrum L. , Sp. Pl. 1022 (1753).

Stems procumbent to ascending; young twigs minutely glandular-puberulent, soon glabrous. Leaves 3-7 x 1-2 mm, linear-oblong to narrowly elliptical, glandular when young, glabrous later; margins closely approximated but not or only slightly involute, whitish, so that the apparent abaxial surface of the leaf bears a pale stripe or shallow groove. Sepals and petals c. 1 - 5 mm, oblong, greenishpink to reddish-purple. Stamens up to 5 mm, long-exserted. Stigma sessile, with 6-9 rays. Drupe 5 mm in diameter, black. Heaths, moors, coniferous forests and stony mountain-slopes. N. Europe, and on mountains southwards to the Pyrenees, C. Italy, Bulgaria and S. Ural. Al Au Be Br Bu Cz Da Fa Fe Ga Ge Hb He Ho Hs Is It Ju No Po Rm Rs (N, B, C, W) Sb Su.

The genus consists of a number of closely related taxa (for the most part American) which are variously treated as species, subspecies or varieties. The two European taxa, here treated as subspecies, are.often regarded as separate species, largely because of their difference in chromosome number; but the correlation between chromosome number and reproductive pattern, though good, is not perfect (the latter being possibly susceptible to environmental influences), and the differences in vegetative characters show some overlap.