l8 9 1 -] A key to the North American Labiatcz. 51 



P Stamens 4 (Q). 

 P Stamens 2 (S). 

 Q Stamens arcuate, shorter than the corolla; calyx about equally 



5-toothed. . . . Micromeria, 18* ' 



Q Stamens ascending under the upper lip (K). 



R Corolla tube straight, mostly exceeding the calyx; throat com- 

 monly enlarged. . . . Calamintha, 19. 



R Corolla tube straight, bent backward at the throat, ringent, shorter 

 than the calyx; leaves linear, margins revolute.. . .Conradina, 21. 



R Corolla tube declined at base, then ascending, included in the 

 calyx; leaves ovate, serrate .... Melissa, 20. 



S Fruticulose and canescent; calyx -terete and regular; equally 

 5-toothed or nearly so; corolla mostly with a hairy ring within. .. . 



Foliomiiitha, 22. 



S Low herbs; calyx usually gibbous, more or less bilabiate or une- 

 qually 5-toothed; corolla tube naked... .Hedeoma, 23. 



T Calyx deeply and unequally 5-cleft, campanulate or turbinate, 

 ciliate, throat naked. . . . Poyoffyne, 24. 



T Calyx bilabiate, nearly terete, throat villous; leaves linear, entire 



... .Cerantliera, 25. 



U Calyx bilabiate, throat naked, teeth acerose-spinulose; stamens 

 inserted high in the ampliate throat, anther cells 2, divaricate.... 



Acanthomintha, 26. 



V Calyx bilabiate, lower lip 2-cleft (W). 



V Calyx tubular or bilabiate with lower lip 2-toothed (X). 



W Corolla upper lip erect, usually concave; stamens on the throat; 

 connective linear or filiform, transverse on the short mostly horizon- 

 tal filament. . . .Salvia, 28. 



W Corolla upper lip spreading; filaments exserted, seemingly sim- 

 ple, anthers linear, 1 -celled; calyx deeply cleft as if spathaceous, throat 

 naked Aubertia. 29. 



X Calyx nearly regular, 5-toothed, orifice more or less hirsute .... 

 Monarda, 30. 



X Calyx bilabiate, throat naked, teeth subulate.. . .Bleplrilia, 31. 



Y Anthers not approximate in pairs, the cells parallel (Z). 



Y Anthers more or less approximate m pairs, the cells divergent; 

 filaments not exserted (ZZ). 



Z Stamens divergent or distant, exserted. . . . Lopliantlius, 32. 



Z Stamens parallel, ascending. . . .Ccdronella, 33. 



ZZ Calyx about equally 5-toothed, throat more or less oblique. . . . 



Nepeta, 34. 



ZZ Calyx upper tooth much larger than the others, throat equal 



.. . .Dracot'cphaliNL 35. 



