Among dogwoods there are two semi-herbaceous
dwarf species that send their woody stems horizontally under litter
and produce clones of low annual shoots--"herbaceous plants" whose stems
are woody only at the very bottom. Both species are distributed in
the Old and New World (circumpolar, with disjunct range). C. canadensis has three separate areas of distribution in the forests of
East Asia and northwestern and northeastern North America.
The other species is even more a northerner and grows in the tundra (it does not occur in Massachusetts).
There are areas where ranges of the two dwarf cornels overlap, and there they can form hybrids.