TRIBE I.—ERICEÆ.
Fig. 47.—The Besom Heath (Erica Tetralix). This tribe, which comprehends all the heath-like plants, has been re-divided into two sub-tribes, one containing the genera most nearly allied to the heaths, and the other those be longing to the Andromeda. In both there is a honey-bearing disk under the ovary, and the leaves are generally rolled in at the margin, as shown at a, in fig. 47.
SUB-TRIBE I.—ERICEÆ NORMALES.
All the genera in this sub-tribe, twenty-two in number, were formerly included in the genus Erica; and some botanists still consider all the species to belong to that genus, with the exception of those included in Calluna, while others adopt about half the new genera. In this uncertainty, I shall only describe two of the doubtful genera, partly because the distinctions between them and the true heaths are strongly marked, and partly because the species they contain are frequently met with in British gardens and greenhouses, where they are sometimes labelled with their old names and sometimes with their new ones.
In the genus Erica, one of the commonest species is the Besom Heath (E. tetralix), which is found in great abundance on moorish or boggy ground in every part of Britain. In this plant, the corollas of the flowers appear each to consist of a single petal, forming an egg-shaped tube (see b in fig. 47), contracted at the mouth, but afterwards spreading into a four-cleft limb, through which is seen projecting the style, with its flat stigma. The corolla is, however, really in four petals, which, though they adhere together, may be easily separated with a pin. The stamens are concealed by the corolla, but the manner in which they grow is shown at c; and d is a single stamen, showing the spurs or awns at the base of the anther, the position of which is one of the characteristics of the genus Erica in its present restricted form; e is a capsule with the style and stigma attached; and a is a leaf showing its revolute or curled back margin. The leaves of this species are in whorls, four leaves in each whorl, and they are ciliated, that is, bordered with a fringe of fine hairs.
All the true Heaths bear more or less resemblance to this plant. In some, the corollas are bell-shaped, spreading out at the tip into five teeth, which inclose the stamens, as shown in fig. 48; and in others they are nearly globose swelling out near the calyx, and tapering to a
