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

	rays spreading-ascending to divaricate; NOT [rays ascending or spreading-ascending]
	bractlets of inflorescence present and persistent; NOT [bractlets absent or very small and caducous]
	flowers white; NOT [flowers yellow or greenish]
	styles 2-3 mm long; NOT [styles less than 0.5 mm long]
	fruit 18-22 mm long; NOT [fruit 10-20 mm long]
	fruit base long-tapering, becoming caudate with conspicuous tales]; NOT [fruit obtuse at base, not caudate]
	fruit bristly-hispid; NOT [fruit glabrous]

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]