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

	most of the leaves deeply 3-lobed
	leaves with veins radiating from base; NOT [leaves with veins pinnate from midrib]
	inflorescence branch with 2 pairs of leaves; NOT [inflorescence branch with 1 pair of leaves]
	outer flowers of cyme larger, sterile; NOT [outer flowers of cyme similar to rest]

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

	erect shrubs; NOT [trees], NOT [low, slender, trailing evergreen shrub]
	leaves simple, at most deeply lobed; NOT [leaves pinnately compound]
	leaves toothed or lobed; NOT [leaves entire or undulate]
	inflorescence all terminal in compound cymes; NOT [inflorescence axillary as well as terminal]
	corolla rotate; NOT [corolla tubular or bell-shaped]
	flowers with 5 stamens; NOT [flowers with 4 stamens]
	fruit a drupe containing a flattened stone; NOT [fruit a capsule or berry with 2 or more seeds]

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

	shrubs; NOT [herbs], NOT [trees]
	large shrubs; NOT [dwarf shrubs]
	leaves opposite or whorled; NOT [leaves alternate]
	stems bearing few to several flowers; NOT [stems bearing a solitary flower]
	stamens 5; NOT [stamens 5-10], NOT [stamens 2]
	ovary inferior; NOT [ovary superior]
	fruit fleshy; NOT [fruit a capsule]