A low, evergreen, heath-like shrub about 1 ft high in gardens, with spreading, wiry, procumbent stems, minutely downy when young. Leaves narrow-linear, 1⁄8 to 1⁄4 in. long, sometimes arranged in fours, but usually arranged indiscriminately on the shoot, always crowded, blunt at the apex, dark green with a white line beneath, margins much decurved. Flowers unisexual, with the sexes on different plants, produced during March singly in the leaf-axils near the tips of the previous summer’s shoots. They are very small, and the only conspicuous part is the stamens, of which there are three to each male flower; they are pinkish, and have long, very slender stalks holding the anthers slightly beyond the leaves. The fruit is an orange-shaped black berry, 3⁄16 in. wide, borne in clusters near the end of the twigs, each containing six to nine seeds.
If interpreted in a broad sense, this species is widely distributed in high latitudes in the northern hemisphere and in the mountains of lower latitudes, but many of its reported locations would belong to E. hermaphroditum if that is recognised as an independent species. The crowberry is not common in gardens, but it thrives very well in the London district and makes a low, dense, neat mass of greenery, easily increased by cuttings. It is a moorland plant, and an associate of the heather, cranberry and whortleberry, and likes a sandy, peaty soil. The fruits are edible but not very desirable.
f. purpureum (Raf.) Fern. E. purpureum Raf. – Berries reddish purple. Found in various parts of N. America.
E. hermaphroditum (Lange) Hagerup E. nigrum f. hermaphroditum Lange – Flowers hermaphrodite (not unisexual as in E. nigrum) habit denser and more erect. Young stems dull green. This species, only recently separated from E. nigrum, appears to have a fairly wide distribution including Scotland.