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

	bractlets of inflorescence absent or very small and caducous; NOT [bractlets of inflorescence present and persistent]
	rays and pedicels wide-spreading or reflexed; NOT [rays and pedicels usually ascending]
	flowers white; NOT [flowers yellow or greenish]
	fruits mostly shorter than the pedicels; NOT [fruits longer than the pedicels]
	fruit 10-20 mm long; NOT [fruits about 10 mm long], NOT [fruits 18-25 mm long]
	fruit clavate, the apex convexly narrowed; NOT [fruit cylindrical, the apex concavely narrowed (constricted) into a beak 0.5-2.0 mm long]
	base of fruit long-tapering, becoming caudate with conspicuous tails; NOT [fruit obtuse at base]
	fruit bristly-hispid; NOT [fruit glabrous]
	styles less than 0.5 mm long; NOT [styles 2-3 mm long]

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

	plants NOT with a bluish tinge
	foliage NOT spiny
	lowest leaves (and the upper) compound
	leaves divided into few well-developed leaflets; NOT [leaves much divided, with leaflets or segments numerous]
	leaves with more than 3 leaflets
	leaves often divided into 5 or more segments; NOT [leaves usually divided into 3 segments each with 3 leaflets]
	leaves ternately divided; NOT [leaves palmate with 5-7 large leaflets], NOT [foliage digitately compound] , NOT [leaves pinnately divided]
	leaves divided into leaflets of unequal size; NOT [leaves divided into leaflets of about equal size]
	leaflets NOT palmate
	leaflets NOT 10-30 cm wide
	leaflets finely to deeply serrate; NOT [leaflets entire or with a few lobes]
	plants lacking axillary bulblets; NOT [plants with axillary bulblets largely replacing flowers]
	inflorescence NOT bluish
	flowers NOT in dense globose heads
	bracts NOT spiny
	fruit several times longer than broad; NOT [fruit generally 3 times as long as broad or less]
	fruit linear to clavate; NOT [fruit oblong to elliptical]
	fruit more than 1 cm long
	fruit flattened but wingless; NOT [fruit strongly flattened, broadly winged]
	fruit usually bristly-hairy (glabrous in O. occidentalis) ; NOT [fruit glabrous]
	fruit NOT covered with short, hooked spines

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

	herbs; NOT [shrubs or trees]
	plants terrestrial or semiaquatic; NOT [plants aquatic, leaves submerged or floating]
	plants NOT with colored milky juice
	stems hollow
	plants with more than one normal leaf
	some or all leaves alternate; NOT [leaves opposite, whorled, or basal]
	leaves without stipules, or having glands; NOT [leaves with stipules]
	flowers in umbels
	parts of flowers mostly in fives; NOT [parts of flowers in twos or fours]
	flowers with two floral rings, and with each petal distinct from the others]
	calyx regular; NOT [calyx irregular, some sepals smaller than others]
	stamens 10 or fewer; NOT [stamens usually more than 10]
	ovary inferior
	styles 2; NOT [styles 5]