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

	leaves broader; NOT [leaves mostly oblanceolate, tapering at both ends]
	inflorescence flat-topped; NOT [inflorescence elongate, conical or ovoid in outline]
	inflorescence broad, open; NOT [inflorescence small, dense]
	petals white; NOT [petals pink or roseate]

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

	plants taller; NOT [creeping dwarf shrubs]
	plants NOT spiny
	leaves simple; NOT [leaves compound or lobed], NOT [leaves palmately 3-5-lobed]
	leaves serrate or toothed; NOT [leaves entire]
	flowers usually more numerous; NOT [flowers solitary on a long peduncle]
	calyx NOT stellate-pubescent
	petals 5; NOT [petals usually 8]
	ovary or ovaries superior, hypanthium shaped like a saucer, cup or urn and free from the ovary; NOT [ovary inferior, enclosed in and adnate to the hypanthium]
	carpels 3-5; NOT [carpel 1], NOT [carpels numerous]
	fruit a dry, leathery follicle; NOT [fruit fleshy], NOT [fruit drupelets (raspberry-like)]
	fruit dehiscent

Rosaceae: Answers to key questions in Budd's Flora  leading to this family.  Not all the answers apply to all the members of this family, but they all do apply to Spiraea. 

	shrubs or trees; NOT [herbs]
	plants NOT climbing
	stems NOT armed with prickles
	plants with normal leaves
	leaves alternate; NOT [leaves opposite]
	leaves simple; NOT [leaves compound]
	flowers with two floral rings, and with each petal distinct from the others
	stamens numerous; NOT [stamens less than 10]
	fruit WITHOUT a tongue-shaped bract; NOT [fruit with a tongue-shaped bract adhering to the peduncle]