Viburnum opulus L. var. americanum Ait.

Highbush Cranberry

Caprifoliaceae (Honeysuckle family)

General Description: A coarse shrub or small tree to 4 m tall. Leaves are 4-12 cm long, with three prominent lobes, these coarsely few-toothed or sometimes almost entire, and pointed at the tip. The leaves are also prominently three-veined from the base, the veins often with stiff hairs, at least in part. The inflorescence is 5-15 cm wide on a short peduncle. Marginal flowers are neutral and larger (1.5-2.5 cm wide) than the inner flowers (3-4 mm wide). Corollas are white, flat and circular in outline, and the perfect flowers have protruding stamens. The fruit is a red berry.

Illustration.

Field Identification Tips: Good characters are the strongly three-lobed leaves with three prominent veins, and an inflorescence comprised of smaller flowers ringed by a set of larger marginal flowers.

Phenology: Flowers May-July, but can be recognized in the field throughout the growing season.

Similar Species: Viburnum edule has smaller flowers and leaves much less lobed.

Habitat: Moist woods.

Global Distribution: Newfoundland to southern British Columbia, southward to Pennsylvania, Illinois, South Dakota, Wyoming, Washington, and Idaho.

Idaho Distribution: Apparently known from one or more historical collections from northern Idaho. It has not been collected in many years and may be extirpated from the state.