196 SOLANACEAE (POTATO FAMILY) 



BB. Leaves not paler beneath, veins prominent. E. M. nervosa 



AA. Leaves not so beneath. 



C. Plant somewhat canescent. U. M. villosa 



CC. Plant glabrous or puberulent except the inflorescence. 



D. Leaves not as long as the stem internodes. U. E. M. reflexa 



DD. Leaves mostly longer than the stem internodes. 



E. Plant very smooth and shining except the inflorescence; leaves obtuse. E. 



M. purpurea 

 EE. Plant somewhat ashy-gray with scurfy puberulence; leaves acute. E. 



M. odoratissima 



LYCOPUS (WATER HOREHOUND) 



Flowers small, white or purple, bracted, whorled in dense axillary clusters. 

 Calyx 4~5-toothed. Corolla equaling or exceeding the calyx; limb either 

 nearly equally 4-cleft or else one of the lobes wider and emarginate. (Gk. 

 lykos = a wolf, pous = a foot ; from a fancied resemblance in the leaves.) 



A. All of the leaves or all but the upper ones irregularly incised or laciniate-pinnatifid. 

 W. E. L. americanus 



AA. Leaves merely serrate. 



B. Calyx teeth lanceolate or deltoid, obtuse or barely acutish, shorter than the 



mature nutlets. W. C. E. L. uniflorus (BUGLEWEED) 



BB. ' Calyx teeth narrow, very acute, longer than the mature nutlets. 



C. Leaves short-petioled; bracts about half the length of the calyx; corolla almost 



twice as long as the calyx. W. L. rubellus 



CC. Leaves sessile or very short-petioled; bracts almost as long as the calyx; 



corolla very little longer than the calyx. E. L. lucidus 



MENTHA (MINT) 



Erect or diffuse. Flowers purple or pink or white ; whorls axillary or in 

 terminal spikes. Calyx lo-veined, 5-toothed. Corolla tube shorter than 

 the calyx; limb 4-cleft, slightly irregular; upper lobe usually wider, entire 

 or emarginate. Stamens 4, equal. (Minthe was a nymph whom the 

 Greeks believed was changed into a Mint.) 



A. Stems finely retrorse-pubescent at least on the angles; flowers in the axils of ordi- 

 nary leaves. W. C. E. M. canadensis (FIELD MINT) 

 AA. Stems glabrous or nearly so, hairs when present not retrorse; most of the flowers 



in the axils of bracts. 



B. Leaves sessile or nearly so; flowers sessile. W. E. M. spicata (SPEARMINT) 



BB. Leaves petioled; flowers pedicelled. 



C. Calyx teeth hairy; leaves ovate-oblong to lance-oblong, acute; garden escape. 

 W. M. piperita (PEPPERMINT) 



CC. Calyx teeth glabrous; leaves ovate, obtuse or the upper acute. W. E. 



M. citrata (BERGAMOT MINT) 



SOLANACEAE (POTATO FAMILY) 



Herbs or shrubs, sometimes vines. Leaves alternate, pinnately 

 veined; stipules none. Flowers perfect, regular. Calyx mostly 

 5-toothed or -lobed. Corolla rotate to tubular, mostly 5-lobed. 



