478 ORDER LABIATE, OR MINT TRIBE. 



undiscoverable, a character that shows the alliance of this group 

 to the Convolvulus tribe, with which it is said also to agree, in 

 the possession of purgative properties. 



654. The next order we shall notice is also a large one, 

 chiefly consisting, however, of humble plants ; but these attract 

 attention from their aromatic character, which occasions many of 

 them to be cultivated by Man for various purposes ; and also 

 from their great abundance, especially in the northern temperate 

 regions. The order now alluded to is that of LABIATE, or 

 Labiate plants, so named from the peculiar form of the corolla, 

 which seems to have a pair of lips; we may designate it as the 

 Mint or the Dead-Nettie tribe, from some of its best-known 

 species. In all the preceding orders of this sub-class, both calyx 

 and corolla have been regular ; that is, their parts are equal, or 

 nearly so. In the Labiatee, however, this is not the case. The 

 calyx is a little cup, with five teeth at its edge, which are some- 

 times equal ; but in general it is divided by a deeper cleft, into 

 two unequal lips, of which one has three teeth and the other 

 two. The corolla is tubular at the base, but is divided above 

 into two unequal lips, of which the upper one is narrow and 

 concave, whilst the lower one is broad and convex ; the upper 

 consists of two adherent petals, and the lower one of three, of 

 which the central one is usually the broadest. There can be no 

 difficulty in recognising a labiate corolla from this description ; 

 but the plants belonging to the order may be even more readily 

 distinguished by their stamens. These are four in number, lying 

 within the tube of the corolla ; and two are longer than the 

 rest ; so that their character is, in the Linnsean language, Didy- 

 namous, and the whole group corresponds with the first order of 

 the Linnaean class DIDYNAMIA. In some instances, however, 

 only two stamens are present. The anthers are peculiar in the 

 great separation of the lobes, which touch each other only at 

 their points; in the Sage, only a single lobe is developed (. 432). 

 The ovarium externally presents four divisions, from which it 

 might be supposed to consist of four carpels ; in reality, how- 

 ever, there are only two cells, each of which contains two ovules; 

 and these four seeds, being large, give the form to the seed- 



