414 THE XABIATE FAMILY. 



been long cultivated. Occurs occasionally in Britain under similar circum-_ 

 stances. Fl. end of summer. It is not improbably a mere variety of the" 

 horse M., of garden or accidental origin, rendered perpetual by its ready 

 propagation by suckers. 



4. Pepper Mint. DIentlia piperita, Sm. 



(Eng. Bot. t. 687.) 



A perennial, less erect than the spear M., glabrous like that species or 

 nearly so. Leaves more stalked and broader. Spikes fuller, consisting of 

 larger whorls ; the lower ones often distant, showing an approach to the cha- 

 racter of the water M. 



The common pungent variety appears to be of garden origin, occasionally 

 spreading in wet places in several jiarts of Europe. Indicated in several lo- 

 calities in England and Ireland. Fl. end of summer. It may possibly prove 

 to be a mere variety of the water M. 



5. '^Vater Mint. Mentha aquatica, Linn. 



{M. hirsuta, Eng. Bot. t. 447, and M. odorata, t. 1025.) 

 Usually a rather coarse perennial, 1 to 1| feet high, much branched, and 

 almost always softly liaii-y, although some varieties become nearly glabrous. 

 Leaves stalked, ovate or slightly heart-shaped. Flowers larger than in the 

 horse M. and the round-leaved M., in dense, terminal, globular or oblong 

 heads, of more than half an inch in diameter, with occasionally 1, 2, or 

 more additional whorls in the axils of the upper leaves. Calyx tubular, 

 about Ij lines long, with fine pointed teeth. 



In wet ditches, and marshes, and on the edges of streams, throughout 

 Europe and Russian Asia, and now naturalized in many other countries. 

 Abundant in Britain generally, but, like the two following, becomes rarer in 

 the north of Scotland. Fl. summer and antumn. 



6. ^Vhorled Mint. Mentha sativa, Linn. 

 (Eng. Bot. t. 448, and M. aetit folia, t. 2415.) 



Intermediate, as it were, between the water M. and the corn M., this plant 

 has the foliage and calyx of the former, but the stem is less erect and often 

 low and spreading, as in the corn M., and the flowers, as in the latter spe- 

 cies, are all in distinct axillary whorls, without any terminal head or spike, 

 or with only a very few flowers in the axils of the last pair of floral leaves. 

 Its chief difference from the corn M. is in the more tubular, longer calyx, ^nd 

 larger flowers ; but mtermediate forms are so numerous, connecting it on the 

 one hand with the corn M. and on the other with the water M., that many 

 botanists have considered it as a mere variety of the one or of the other. ' 

 These points cannot be determined without a long course of experiments and 

 observations made on a succession of seedlings, which are as rare in this as 

 in other species of the genus. 



As widely spread as the corn M., all over temperate and northern Europe, 

 and Russian Asia, but growing usually in moister situations and richer soils. 

 Common in Britain. Fl. summer and autumn, 



7. Corn Mint. Mentha arvensis, Linn. 

 (Eng. Bot. t. 2119, M. agrestis, t. 2120, and M. gentiUs, t. 449 and 2118.) 

 Usually a low, spreading, branched perennial, more or less hairy, with a 

 qreeping rootstock, and annual stems, from 6 inches to a foot long, rarely 



I 



