The new order Cyrtandraceæ, including Æschynanthus, Streptocarpus or Didymocarpus, Fieldia, and Amphicoma, is introduced here: the first and last of these genera are new, and the others were formerly included in Bignoniaceæ.
[Illustration: FIG. 141.--A LABIATE FLOWER.]
[Illustration: FIG. 142.--BLACK HOREHOUND (_Ballota nigra_).]
The plants belonging to this order include Mint, Sage, Thyme, and other kitchen aromatic plants, and several well-known British weeds. They are all distinguished by a tubular, bilabiate corolla with a projecting under lip (see _a_ in fig. 141). In some plants the corolla is ringent, as shown in fig. 142, taken from Dr. Lindley's _Ladies' Botany_, in which _a_ is the galea or helmet, and _b_ the lower lip, which is three-lobed. There are four stamens, two of which are longer than the others, and the cells of the anthers differ from those of most other plants in spreading widely apart from each other, each being joined to the filament only at the tip. The pistil consists of four distinct carpels (_c_), a very long style lobed at the tip, and furnished with a very small stigma at the tip of each lobe (_d_). The flowers of some of the plants belonging to this order are disposed in a whorl round the stem; as, for example, those of the Dead Nettle (_Lamium_). Among the other plants belonging to the order may be mentioned the Bugle (_Ajuga_), and the Ground Ivy (_Glechoma_), both common but very pretty British weeds.
ORDER CXLIII.--VERBENACEÆ.--THE VERVAIN TRIBE.
The genus Verbena is well known, from the many beautiful species now common in every greenhouse. The fruit is two or four celled, and a drupe or a berry, and the calyx of the flowers is tubular, and persistent round it; but the corolla is deciduous, and falls off long before the fruit is ripe. In the genus Verbena the calyx is tubular, with five distinct angles, ending in five teeth. The corolla has a cylindrical tube nearly double the length of the calyx, and a flat limb divided into five unequal segments, which are wedge-shaped and notched, the central one of the lower three appearing to have been slightly pinched; the throat of the corolla is hairy. There are four stamens, two longer than the others, the anthers having two widely-spreading lobes, as in the Labiatæ. The style is slender below, and thickest in the upper part; and the stigma is two-lobed. The leaves are opposite, and furnished with stipules The flowers form a corymb in the Scarlet Verbena, and a spike in some of the other kinds, which elongates gradually as the flowers expand. The principal other genera are Clerodendron, or Volkameria, Vitex (the Chaste-tree), Lantana, Aloysia (the Lemon-scented Verbena), and Tectona (the Teak) which is so much used in the East Indies for ship-building.