LABIATE. 645 



III. MINT. MENTHA. 



Perennial herbs, usually downy or hairy, with rather small flowers 

 in dense whorls or clusters, which are either collected in terminal 

 heads or spikes, or axillary and distant. Calyx of 5 teeth, regular or 

 slightly 2-lipped. Corolla with a short tube and a campanulate 4- 

 lobed limb, the upper lobe rather broader and sometimes slightly 

 notched. Stamens 4, equal and erect, the anthers 2-celled. Nuts 

 smooth, not bordered. 



A natural genus, not numerous in species, but widely diffused over 

 the greater part of the globe without the tropics, and most of the 

 species, from the variety of situation to which they will adapt them- 

 selves, vary so much as to render their exact definition almost hope- 

 less. Many of them also propagate so readily from suckers, that indi- 

 vidual varieties are perpetuated so as to assume the appearance of 

 species. Almost all the species vary in the stamens, in some indivi- 

 duals much longer than in the corolla, in others included within the 

 tube, and often barren ; and in several species individuals occur with 

 all the leaves crisped and cut, and have been published as distinct, 

 under the names of M. crispa or crispata. 



Whorls of flowers in terminal spikes or heads. 

 Leaves mostly sessile. Flowers in spikes. 

 Leaves and stem downy or hairy. 



Leaves narrow-ovate or lanceolate ......... .1. Horse M. 



Leaves broadly ovate or orbicular 2. Mound-leaved M. 



Leaves and stem glabrous ........ 3. Spear M. 



Leaves all shortly stalked. 



Flowers in cylindrical or elongated spikes ... 4. Pepper M. 

 Flowers in terminal, globular or ovoid heads (rarely 

 with a few dense clusters below the terminal 



one) 5. Water M. 



Whorls of flowers all axillary, the last (terminal) pair 



of leaves having no flowers or only a very small 



whorl. 



Flowering stems ascending or erect. Leaves coarsely 



crenate. Throat of the calyx not closed withhairs. 



Calyx tubular, with narrow teeth 6. Whorled M. 



Calyx campanulate, with short teeth 7. Corn M. 



Flowering stems prostrate. Leaves small. Throat 



of the calyx closed with hairs 8. Pennyroyal M. 



1. Horse Mint. Mentha sylvestris, Linn. (Fig. 773.) 

 (Eng. Bot. t. 686.) 

 Bootstock, as in most Mints, more or less creeping, the stems 1 to 



