GUELDER ROSE, so called from Guelderland, its supposed source, is known botanically as Viburnum Opulus, a shrub or small tree of the honeysuckle family (Caprifoliaceae), a native of Britain, and widely distributed in the temperate and colder parts of Europe, Asia and North America It is common in Ireland, but rare in Scotland. In height it is from 6 to 12 ft., and it thrives best in moist situations. The leaves are smooth, 2 to 3 in. broad, with 3 to 5 unequal serrate lobes, and glandular stipules adnate to the stalk. In autumn the leaves change from bright green to pink or crimson. The flowers, which appear in June and July, are small, white, and arranged in cymes 2 to 4 in. in diameter. The outer blossoms in the wild plant have an enlarged corolla, a in. in diameter, and are devoid of stamens or pistils; in the common cultivated variety all the flowers are sterile and the inflorescence is globular, hence the term "snow ball tree" applied to the plant. The guelder rose bears juicy, red, elliptical berries, 3 in. long, which ripen in September, and contain each a single compressed seed. In northern Europe these are eaten, and in Siberia, after fermentation with flour, they are distilled for spirit. The plant has, however, emetic, purgative and narcotic properties; and Taylor (Med. Jurisp., 1873) has recorded an in stance of the fatal poisoning of a child by the berries. Both they and the bark contain valerianic acid.
The fruit of the North American form (V. Opulus var. ameri canum or V. trilobum), commonly called cranberry-bush or high bush cranberry, found from New Brunswick to British Columbia and southward to New Jersey and Oregon, is prized for jams and jellies, especially in the northern parts of its range, and choice fruiting strains are sparingly cultivated. (See VIBURNUM.)