Jones: Flora of Illinois, 135. Labiatae 217 



10. Stamens not strongly exserted. 



1 1 . Calyx-teeth rigid, spine-tipped; corolla 6-10 mm. long 



13. Leonurus 



1 1 . Calyx-teeth not spine-tipped. 



12. Corolla 12-24 mm. long 14. Lamium 



12. Corolla 7-12 mm. long. 



13. Calyx not 2-lipped. the 5 teeth nearly equal. 



14. Leaves coarsely crenate-denate ; corolla whitish, 7-9 mm. 

 long; stem copiously finely pubescent 7. Nepela 



14. Leaves entire; corolla purple; stem puberulent 



2 1 . Satureia 



13. Calyx 2-lipped, the teeth conspicuously unequal. 



15. Stem erect or ascendmg. 



16. Stem glabrous or sparsely pubescent; flowers in dense 



terminal bracted spikes; stamens 4. 



1 7. Leaves entire or sparingly crenate; floral bracts 



ciliate; calyx reticulate-veiny, somewhat 10- 



nerved 12. Prunella 



17. Leaves coarsely sharply serrate; floral bracts 



pectinate; calyx 13-I5-nerved 



10. Dracocephalum 



16. Stem hirsute; calyx 13-nerved. 



18. Leaves 2-10 cm. long; stamens 2, exserted 



1 7. BlephiUa 



18. Leaves 5-10 mm. long; stamens 4 



22. CUnopodium 



15. Stems prostrate, the flowering branches erect or ascend- 

 ing, pubescent; leaves oval, obtuse, entire, short- 

 petioled, 6-15 mm. long; calyx 2-lipped, the linear 

 teeth ciliate; stamens 4; corolla purplish.. ..23. Thymus 

 6. Flowers in racemes or spikes, or solitary or few in the axils of the leaves. 



19. Calyx deeply 4-cleft; corolla greenish yellow, 3-4 cm. long; flowers solitary, 

 axillary; leaves thin, palmately veined, the blade shorter than the petiole 



1 1 . S\^nandra 



19. Calyx 5-toothed or 2-lipped; corolla smaller. 



20. Leaves reniform, crenate, petioled; stems trailing; flowers blue, axillary 



8. Clecoma 



20. Leaves not reniform. 



21. Flowers 4-6 mm. long. 



22. Leaves linear or lanceolate, entire or sparingly serrate; stamens 2 

 19. Hedeoma 



22. Leaves ovate, coarsely dentate; stamens 4 29. Perilla 



21. Flowers more than 6 mm. long. 



23. Corolla with the upper lip apparently obsolete; stamens erect, 



exserted; flowers in long racemes 1. Teucrium 



23. Corolla conspicuously bilabiate. 

 24. Leaves toothed. 



25. Flowers in loose terminal panicles; corolla light yellow; 



fertile stamens usually only 2; calyx 2-lipped 



28. Collinsonia 



25. Flowers not in loose terminal panicles. 

 26. Calyx nearly equally 5-toothed. 



27. Flowers 1.5-3.5 cm. long; spikes continuous, loosely 



flowered; fertile stamens 4 9. Physosiegia 



27. Flowers 1-1.5 cm. long. 



28. Fertile stamens 2, long-exserted ; plants very 



aromatic; corolla purple; stem glabrous 



25. Cunila 



28. Fertile stamens 4, not long-exserted; spikes com- 

 posed of interrupted whorls 15. Slachys 



