viburnum, (genus Viburnum), any of about 175 shrubs and small trees belonging to the family Adoxaceae, native to temperate and subtropical Eurasia and North America, with about 16 species native to Malaysia. Many species are cultivated for their ornamental foliage, fragrant clusters of usually white flowers, and colourful blue-black fruits.
The American wayfaring tree, or hobblebush (V. alnifolium), native to eastern North America, grows to 3 metres (10 feet) tall; it has roundish leaves, with white flower clusters and red berries that turn purple-black at maturity. The wayfaring tree of Europe, V. lantana, grows to 5 metres (16 feet). The European cranberry, highbush cranberry, or water elder (V. opulus), a small tree reaching 4 metres (13 feet), is native to northern Europe and North Africa. It has three- to five-lobed, maplelike leaves and round heads of white flowers that are followed by hanging clusters of shiny, bright red, translucent berries. The leaves turn red in autumn. V. trilobum, from northern North America, is similar but has short-stalked flowers and three-lobed leaves.
A variety of the European cranberry, V. opulus variety roseum, is known as snowball, or guelder rose, for its round, roselike heads of sterile florets. Chinese snowball (V. macrocephalum variety sterile) and Japanese snowball (V. plicatum) are common snowball bushes with large balls of white to greenish white flowers. The 4.5-metre- (15-foot-) high black haw (V. prunifolium), of eastern North America, has plumlike leaves, small white flower clusters, and blue-black berries.
Other North American species are the southern black haw (V. rufidulum), similar but taller; the sheepberry, or nannyberry (V. lentago), with finely toothed, oval leaves; and the arrowwood (V. dentatum), with roundish to oval, coarsely toothed leaves. Laurustinus (V. tinus), a 3-metre-tall evergreen with oblong leaves, is native to the Mediterranean area. Sweet viburnum (V. odoratissimum), from India and Japan, bears dark-green, shiny, evergreen leaves and large clusters of fragrant flowers.