Trees of Wisconsin
Cornus alternifolia L.f.
woody species in the genus Cornus can be recognized by the simple,
opposite, unlobed, entire leaves and the "arcuate" venation
in which the veins curve toward the tip of the leaf as they branch outward
from the midrib of each leaf, becoming nearly parallel to the margin as
they near it. Cornus alternifolia is the only species of Cornus
in Wisconsin that has alternate leaves and it is also the only naturally
occurring species of Cornus that has the growth form of a tree--all
the others (4) being clearly shrubs. The leaves are strongly clustered
toward the ends of the branches. The numerous small, white, 4-petaled
flowers in flat-topped inflorescences open in May or June and are similar
to the other Cornus species. The berry-like fruits turn blue when
ripe, toward the end of the summer.
The growth form is very distinctive because the nearly horizontal branches, although alternate, tend to develop in groups of 3-5 very close together, followed by a relatively long section of trunk with no branches, followed by another aggregation of branches. The result is a conspicuous "layered" look that can be seen in the photo of the tree above.
Cornus alternifolia ranges from Nova Scotia through southern Ontario to Minnesota, south to Missouri and Pennsylvania and in the Appalachian mountains to northern Georgia. It is found throughout Wisconsin in a variety of forests, as an understory species.