Flower Side (Bract)
Moose Mountain Provincial Park
Both Budd's Flora and Flora of Alberta classify this species as Convolvulus sepium. However, other treatments such as Flora of China, Checklist of the Vascular Plants of Saskatchewan, and Flora of the Great Plains place it in genus Calystegia. Therefore I have used the answers from the species and genus keys in Flora of the Great Plains, but have still used the answers from the family key in Budd's Flora, in the lists below. Budd's Flora still includes genus Cuscuta in family Convolvulaceae (unlike more recent treatments), but the key answers listed below all just pertain to the non-Cuscuta portion of the family.
Flora of China states that nearly all the taxa in Calystegia intergrade geographically into neighboring taxa and that the species boundaries are largely arbitrary.
Sepium: Answers to key questions in Flora of the Great Plains leading to this species.
Calystegia: Answers to key questions in Flora of the Great Plains leading to this genus.
Convolvulaceae: Answers to key questions in Budd's Flora leading to this family.