SPECIES AND VARIETIES. 295 



M. rotundifolia is a greener^ and more hairy plant, with 

 broadly ovate or orbicular leaves, and terminal cylindrical 

 spikes of small pale pink flowers ; and M. viridis, has glabrous 

 green stems and leaves, the latter acutely lance-shaped, and 

 lax cylindrical terminal flower spikes. This last is the common 

 Mint of our gardens. 



M. piperita : stems 1-1 \ foot high, erect, glabrous, or 

 nearly so; leaves stalked, ovate-oblong, serrated; flowers lilac, 

 in blunt rather dense spikes, the lower whorls often distant. 

 — Peppermint. — Wet places, rather rare. Fl. July, August. 



M. aquatica : stems 1-1^ feet high, much branched, softly 

 hairy, or sometimes nearly glabrous ; leaves stalked, ovate or 

 slightly heart-shaped ; flow^ers in dense, terminal, globular or 

 oblong heads, pale lilac. — Wet ditches, marshes, and edges of 

 streams. Fl. July, August. 



ft Flowers in distant axillary whorls. 



M. sativa : stems more or less spreading or ascending ; 

 leaves stalked, ovate or elliptical serrate; flowers all in dis- 

 tinct axillary whorls, without any terminal head or spike, the 

 calyx tubular, wdth spreading teeth. — Wet places. Fl. July, 

 August. 



M. arvensis : stems low, spreading, branched, hairy, ^-1 

 foot long, rarely erect ; leaves stalked, ovate, toothed ; flowers 

 all in axillary whorls, mostly shorter than the leafstalks, the 

 calyx campanulate. — Fields and moist places. Fl. July to 

 September. 



** Calyx-throat closed with hairs. 



M. Pulegium : stems prostrate, much branched, rooting ; 

 leaves small, elliptical, entire or slightly creiiate, the floral 

 ones still smaller ; flowers in dense axillary whorls. — Penny- 



