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

	shrubs or trees; NOT [herbs, or with a woody base and otherwise herbaceous]
	plants taller; NOT [creeping dwarf shrubs]
	plants NOT spiny
	leaves simple; NOT [leaves compound or lobed]
	leaves serrate or toothed; NOT [leaves entire]
	flowers usually more numerous; NOT [flowers solitary on a long peduncle]
	ovary or ovaries superior, hypanthium free from the ovary; NOT [ovary inferior, enclosed in and adnate to the hypanthium]
	carpel 1; NOT [carpels 2 or more]
	fruit fleshy; NOT [fruit a leathery follicle]
	fruit a red or black drupe with a single stone; NOT [fruit a berry-like pome with several seeds]

Rosaceae: 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
	plants with more than one normal leaf
	some or all leaves alternate; NOT [leaves opposite, whorled, or basal]
	leaves with stipules; NOT [leaves without stipules, or having glands]
	flowers with two floral rings, and with each petal distinct from the others
	flowers regular in shape; NOT [flowers irregular in shape]
	calyx regular; NOT [calyx irregular, some sepals smaller than others]
	stamens usually separate or partly so, not in a column; NOT [stamens numerous, united into a column]
	ovary of one or more carpels, either separate or enclosed by a fleshy receptacle; NOT [ovary of 5 united carpels]