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

	umbels several; NOT [umbels solitary]
	umbels lateral; NOT [umbels terminal]
	corona hoods WITHOUT an incurved horn within

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

	herbs; NOT [shrubs or trees]
	plants green or with some chlorophyll; NOT [plants parasitic or saprophytic, without chlorophyll]
	plants with milky juice
	flowers not in heads or spikes; NOT [flowers in long or short spikes], NOT [flowers in heads or in form resembling a head]
	flowers with two floral rings, but with the petals wholly or partly united forming a tube or bell
	corolla regular; NOT [corolla irregular]
	stamens united; NOT [stamens distinct]
	pollens grains united into a mass; NOT [pollen grains separate]
	styles distinct; NOT [styles united]
	ovary superior; NOT [ovary inferior]