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

	annuals growing from deep taproots; NOT [perennials from creeping rootstocks]
	ears at base of clasping leaves rounded; NOT [ears at base of clasping leaves acutely pointed]
	heads 1.5-2.5 cm wide in flower; NOT [heads 3-5 cm wide in flower]
	fruiting involucre 9-13 mm high; NOT [fruiting involucre 14-24 mm high]
	fruiting involucre glabrous
	achenes 3-ribbed on each side, not wrinkled; NOT [achenes striate and transversely wrinkled]

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

	plants of various habitats; NOT [plants of dry habitats]
	juice milky; NOT [juice watery]
	NOT [stem diffusely branched]
	plants with normal stem leaves; NOT [plants with leaves all basal or with a few reduced leaves on the stem]
	leaves broader and leaf-like; NOT [leaves narrowly linear or scale-like]
	heads few to many, rarely solitary; NOT [heads solitary]
	involucre of 2 or more series; NOT [involucre uniseriate or biseriate]
	florets all ligulate (ray)
	florets all perfect
	florets yellow
	stamens united to form a tube around the pistil
	achenes beakless; NOT [achenes beaked, the pappus born on a disc at the tip]
	achenes flattened, at least twice as wide as thick; NOT [achenes not flattened]
	pappus well developed, at least in part of capillary bristles; NOT [pappus of minute scales or none]
	pappus simple, consisting of bristles only; NOT [pappus double, the outer ring consisting of 5 small scale-like appendages, the inner ring bristles]
	pappus bristles simple; NOT [pappus bristles plumose (branched)]
	pappus white; NOT [pappus brownish or tawny]