“ In Britain ten species are indigenous or naturalized. Mentha viridis, or spearmint, grows in marshy meadows, and is the species commonly used for culinary purposes; it is distinguished by its smooth, sessile leaves and lax tapering flower-spikes. It is probably a cultivated race of the next species, Mentha sylvestris, or horsemint, which chiefly differs from the above in its coarser habit and hairy leaves, which are silky beneath, and in its denser flower-spikes. ”

“ The last two species usually grow on damp waste ground. M. aquatica grows in ditches, and is easily recognized by its rounded flower-spikes and stalked hairy leaves. M. piperita, or peppermint (q.v.) , has stalked smooth leaves and an oblong obtuse terminal spike of flowers; it is cultivated for its volatile oil. M. pratensis belongs to a group which have the flowers arranged in axillary whorls and never in terminal spikes ”