Idaeus: Answers to key questions in Flora of Alberta leading to this species.  The key in Budd's Flora is confusing, so the answers from that key are not included here.

	shrubs; NOT [plants herbaceous or somewhat woody at base]
	plants 0.5-2 m high; NOT [plants less than 3 dm high
	stems (canes) armed with prickles or bristles; NOT [stems unarmed]
	principal leaves compound, 3-5 foliolate; NOT [principal leaves simple and lobed]
	petals 4-12 mm long; NOT [petals 15-20 mm long]

Rubus: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus.  Not all the answers apply to all species in Rubus, but they all do apply to R. idaeus.

	shrubs; NOT [herbs, or with a woody base and otherwise herbaceous], NOT [small trees]
	plants generally taller than 5-15 cm
	leaves compound, distinctly divided into leaflets; NOT [leaves simple]; NOT [leaves lobed, not distinctly divided]
	leaves not linear-dissected; NOT [leaves dissected into linear divisions]
	leaves with 3-5 leaflets; NOT [leaves with 5-11 leaflets], NOT [leaves with 11-17 leaflets]
	sepal bractlets absent; NOT [bractlets alternating with the sepals]
	flowers white; NOT [flowers pink or yellow]
	carpels numerous; NOT [carpel 1], NOT [carpels mostly 5]
	ovary or ovaries superior; NOT [ovary inferior]
	hypanthium shaped like a saucer, cup or urn and free from the ovary; NOT [ovary enclosed in and adnate to the hypanthium]
	fruit more or less fleshy; NOT [fruit dry]
	carpels becoming drupelets (raspberry-like); NOT [carpels becoming achenes, enclosed in a fleshy receptacle]

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

	shrubs or trees; NOT [herbs]
	plants NOT climbing
	plants with normal leaves; NOT [succulent, spiny plants with leaves absent or scale-like, inconspicuous]; NOT [leaves all basal, and tubular or with tentacles for catching insects]
	leaves alternate; NOT [leaves opposite]
	leaves compound; NOT [leaves simple]
	leaflets NOT leathery
	leaflets NOT spinose-tipped
	flowers with two floral rings, and with each petal distinct from the others
	flowers perfect; NOT [flowers dioecious or perfect]
	petals 5; NOT [petal (standard) solitary]
	stamens numerous; NOT [stamens 5]
	fruit NOT a legume