Coefficient of Conservatism:
Coefficient of Wetness:
R. W. Smith
Included in V. opulus in Michigan Flora.
Swamps (both hardwood and coniferous), borders of forests and shores, wet roadsides and ditches; banks and thickets along rivers and streams, fens; and other moist often open ground.
The ripe fruit is red and about the size of a small cranberry; it makes a tasty jelly. Often known as V. opulus var. americanum Aiton or V. opulus subsp. trilobum (Marshall) R. T. Clausen. Variation in the petiolar glands, typically used to distinguish this from V. opulus, is considerable and often cited differences in shape and stalking are not always easy to apply to Michigan material, especially when the glands are additionally distorted by pressing. The gland size differences, however, seem to represent a real discontinuity, and with practice one can readily distinguish the two in the field. Generally, the central lobe of the leaf, especially in the youngest leaves of longer shoots, is more distinctly longer than wide than that of V. opulus, and often less toothed. In our collections of V. opulus, the upper leaf surface is glabrous, except sometimes near the margins, but in V. trilobum there are at least sparse scattered hairs over the entire surface.