Alba: Answers to key questions in Budd's Flora leading to this species. 

	basal leaves cordate- or hastate-based, abruptly joining stalk;  NOT [basal leaves tapering to winged stalks]
	leaves lobed or cleft; NOT [leaves dentate]
	flowers heads nodding; NOT [flower heads erect]
	bracts of involucre not hairy

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

	juice milky; NOT [juice watery]
	stem not diffusely branched
	plants essentially glabrous below the inflorescence; NOT [plants hairy]
	plants with normal stem leaves; NOT [plants with leaves all basal], NOT [stem leaves few, mostly linear or reduced to scales]
	stems leafy throughout or at least to midway up the stem; NOT [stems leafy at the base only, leaves mostly basal]
	heads few to many, rarely solitary; NOT [heads solitary]
	involucre of two or more series; NOT [involucre uniseriate]
	involucre usually of unequal bracts; NOT [involucre of equal bracts]
	bracts of involucre broad; NOT [bracts of involucre narrow]
	bracts of involucre colored; NOT [bracts of involucre green]
	flowers all ligulate (ray)
	flowers all perfect; NOT [flowers pistillate or neuter]
	flowers white or purplish
	stamens united to form a tube around the pistil
	pappus consisting of bristles only; NOT [pappus of minute scales or none], NOT [pappus double, the outer ring consisting of 5 small scale-like appendages, the inner ring bristles], NOT [pappus scale-like at the base, with plumose terminal bristles]
	pappus bristles simple; NOT [pappus bristles plumose (branched)]
	pappus brownish or tawny; NOT [pappus white]
	achenes not flattened; NOT [achenes flattened, at least twice as wide as thick]