References for Apocynaceae
Boivin, B. 1966. Les Apocynaces du Canada. Naturaliste Can. 93:107-128.
Gillett, J.M. 1968. The milkworts of Canada. Can. Dep. Agric. Res. Branch Monogr. 5. 24pp.

Source for the Reference Lists

George W. Douglas, Del Meidinger and Jim Pojar. 1998-2002. Illustrated Flora of British Columbia.