Upper Leaf Bottom
Moosomin Regional Park
Note that the leaf has been flattened somewhat for the purpose of this photograph.
The key in Budd's Flora leading to family Polygalaceae is unsatisfactory. It requires "calyx regular", whereas the calyx of this species is highly irregular. It also requires "each petal distinct from the others", whereas all the petals of this species are connected to each other.
Senega: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.
Polygalaceae: Answers to key questions in Budd's Flora leading to this family.