348 THE LABIATE FAMILY. . [Mentha. 



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 M. arvcnsis, 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. [This 

 includes many distinct British varieties, distinguished as species by 

 some botanists, as M. rubra, Sm., with the nerves of the leaf purple ; 

 M. gracttis, Sm., a very slender form with narrow floral leaves; M. 

 pratensis, Sole., with drooping leaves rounded at both ends; and M. 

 gentilit, Linn., with large floral leaves, the uppermost flowerless.] 



7. M. arvensis, Linn. (fig. 786). Corn M. Usually a low, spreading, 

 branched perennial, more or less hairy, with a creeping rootstock, and 

 annual stems, from 6 inches to a foot long, rarely rising erect to the 

 height of 1 or 2 feet. Leaves stalked, ovate, and toothed, 1 to 2 inches 

 long, or the upper ones smaller. Flowers all in axillary whorls, mostly 

 shorter than the leafstalks ; the last pair of leaves without any or with 

 only very few flowers. Calyx campanulate, seldom above a line long, 

 with short teeth. Corolla twice as long. 



In fields and moist places, in temperate and northern Europe and 

 Russian Asia ; rarer to the southward, but introduced with cultivation 

 into many other parts of the globe. Abundant in Britain, although less 

 so than M. aquatica, and, like that species, becomes rarer towards the 

 north of Scotland. Fl. summer and autumn. It varies much in stature, 

 in hairiness, in the size of the leaves, &c. 



8. M. Pulegium, Linn. (fig. 787). Pennyroyal. A prostrate, much 

 branched perennial, with the leaves very much smaller than in any 

 other Mentha, being seldom above half an inch long, and quite entire or 

 seldom slightly crenate ; the floral ones still smaller, and often recurved. 

 Flowers in dense axillary whorls, like those of M. a'fvensis, except that 

 the calyx-teeth are less regular, with the mouth closed by hairs, and 

 the upper lobe of the corolla is more evidently notched, thus showing 

 a slight approach to the characters of Thymus. 



In wet ditches, and marshy places, most abundant in the Medi- 

 terranean region, but extending over Europe and western Asia, and 

 introduced into other parts of the world. Scattered over the greater 

 part of England, Ireland, and the south of Scotland. Fl. end of summer. 



IV. THYMUS. THYME. 



Low, much branched, spreading or procumbent undershrubs or herbs 

 with small leaves, usually entire, and flowers in terminal leafy heads or 

 loose spikes. Calyx 2-lipped ; the upper lip 3-toothed, the 16wer 2-cleft, 

 the mouth closed with hairs after flowering. Corolla with the upper 

 lip erect, nearly flat ; the lower spreading, broadly 3-lobed. Stamens 

 (when perfect) 4, the lower ones diverging, as long as or longer than 

 the corolla. 



A genus of several species, chiefly from the Mediterranean region 

 and central Asia, where they are very variable and difficult to determine. 

 In northern Europe, however, there is but one species wild. The garden 

 Thyme, cultivated as a potherb, is T. vulgaris, from southern Europe, 



