Ledinghamii: Answers to key questions in Flora of the Great Plains leading to this species. 

	calyx and rachis of inflorescence bearing stipitate glands
	corolla 14-23 mm long; NOT [corolla 9-12 (16) mm long]
	corolla eglandular; NOT [corolla usually stipitate glandular]
	nutlets 2.8-4 mm long; NOT [nutlets 2.1-3.3 mm long]

Physostegia: Answers to key questions in Budd's Flora leading to this genus. 

	inflorescences terminal; NOT [inflorescences axillary]
	inflorescence a more or less elongated raceme; NOT [inflorescence a more or less globose head]
	inflorescence a raceme of oppositely placed flowers; NOT [inflorescence a raceme of oppositely placed clusters of flowers]
	calyx indistinctly or not at all 2-lipped, one lobe may be larger than the others; NOT [calyx distinctly 2-lipped, the upper lip 3-toothed, the lower one 2-lobed]

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

	herbs; NOT [shrubs or trees]
	plants not aquatic
	plants green or with some chlorophyll
	stems square
	leaves opposite
	leaves not bearing bladders
	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
	petals wholly or partly united forming a tube or bell
	corolla irregular; NOT [corolla regular]
	ovary superior; NOT [ovary inferior]
	fruit with 4 nutlets; NOT [fruit a many-seeded capsule]