Occidentalis:  Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.   usually found along streams; NOT usually found in forests, hills, or dry bogs small tree or large shrub; NOT large tree; NOT low shrub bark of trunk NOT separable into thin layers bark reddish, grayish brown, or brown; NOT whitish or silvery gray leaves mostly 2.5-5 cm long; NOT 4-8 cm long; NOT 1-2.5 cm long leaves usually doubly serrate; NOT simply serrate or crenate leaves indistinctly reticulate; NOT distinctly reticulate wings usually broader than the nutlet; NOT narrower

 

Betula: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.  staminate flowers usually three in the axils of the catkin bracts; NOT solitary in the axils of the catkin bracts stamens 2; NOT 4 pistillate catkins elongated; pistillate flowers NOT in a short, bud-like catkin; pistillate flowers NOT few bracts of pistillate catkins thin, 3-lobed, deciduous; NOT becoming thick and woody, NOT persistent fruit a winged nutlet in the axil of a catkin bract; NOT a nut enclosed in a leafy, hispid involucre nutlets mostly broadly winged; NOT wingless, NOT narrow-winged, NOT with leathery margins

 

Betulaceae: Answers to key questions in Budd's Flora leading to this family. shrubs or trees male flowers, at least, in catkins or aments styles 2; NOT 3 seeds WITHOUT tuft of hairs fruit NOT an acorn