This species will hybirdize with both B.glandulosa and B.papyrifera creating much variation and some confusion.
Biology
Physiology:
All of our birches can hybridize with eachother.
When B.glandulosa (Dwarf Birch) hybridizes with B.papyrifera (Paper Birch) the result is a shrub/tree that is very much like B.occidentalis (Water Birch). It has been suggested that B.occidentalis may be of hybrid origin.