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 MM. arvensis, 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 /. rubra, Sm., with the nerves of the leaf purple ; 
M. gracilis, Sm., a very slender form with narrow floral leaves; JM. 
pratensis, Sole., with drooping leaves rounded at both ends; and M@.. 
gentilis, Linn., with large floral leaves, the uppermost flowerless. ]_ 
7. M. arvensis, Linn. (fig. 786). Corn 1/.—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. summerand 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/. arvensis, 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 lower 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 7. vulgaris, from southern Europe. i - 
