Deltoides: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species. 

	bark of trunk deeply furrowed; NOT [bark of trunk (well above base) smooth (FOA)
	bark of trunk usually grey; NOT [bark of trunk light green or whitish] (FOA)
	leaf blades broadly deltoid to cordate; NOT [leaf blades suborbicular] (FOA)
	leaves NOT coarsely toothed (BF)
	leaf margins coarsely dentate; NOT [leaf margins finely crenate] (BF)
	leaf blades coarsely toothed, often crenate; NOT [leaf blades crenulate or nearly entire] (FOA)
	leaf blades 5-10 cm long; NOT [leaf blades 2-6 cm long] (FOA)
	petioles strongly flattened laterally; NOT [petioles circular in cross-section, not flattened] (FOA)

Populus: Answers to key questions in Budd's Flora  and Flora of Alberta leading to this genus. 

	trees; NOT [mostly shrubs]
	winter buds covered by several scales; NOT [winter buds covered by a single scale]
	catkins soon drooping; NOT [catkins erect or divergent, rarely drooping]
	bracts below flowers mostly lacerate; NOT [bracts below flowers entire or merely toothed]
	flowers with a broad or cup-shaped disk; NOT [disk none]
	stamens usually more than 10; NOT [stamens 2-10, often 2]

Salicaceae: Answers to key questions in Budd's Flora  leading to this family. 

	shrubs or trees; NOT [herbs]
	flowers with only one floral ring, with sepals but not petals
	male flowers, at least, in catkins or aments; NOT [flowers not in catkins or aments]
	seeds each with a tuft of hairs; NOT [seeds without a tuft of hairs]