SUB-TRIBE II.—ANDROMEDEÆ.
The plants in this sub-tribe differ decidedly from those of the preceding division, in having ten stamens, while all the genera of heaths have only eight. The calyx is also five-cleft instead of four; and the corolla, which falls before the seeds are ripe, has a five-lobed limb. The sub-tribe is divided into twenty genera, more than half of which are perfectly distinct.
The genus Andromeda is distinguished by its globose corolla which has a five-lobed limb; and its stamens which have their filaments bearded, and their anthers short and two-awned.
Fig. 52.—Stamen of Andromeda. Fig. 52 shows a stamen of the wild rosemary (Andromeda polifolia) with its bearded filament (a), and its two-awned anther with its pore-like openings (b). The cells of the capsule open in the middle, down the back, to discharge the seeds. Professor Don has divided the genus Andromeda into six genera; some of which contain only one or two species. Thus only Andromeda polifolia and A. rosmarinifolia are left in the genus Andromeda; Cassandra contains only A. calyculata, and A. angustifolia; and Zenobia, only the beautiful Andromeda speciosa. In Cassandra the anthers
Fig. 53.—Leaf and anther of Cassandra. are long and mutic (see a in fig. 53), and the leaves (b) are without veins, and white and full of dots on the underside, the edges being curled inwards; and in Zenobia the corolla is bell-shaped, with the limb, which is in five lobes, curling back (see a fig. 54). The stamens have the filaments (b) curiously dilated at the base; and the point of each cell of the anther is cut into two erect awns (c). The manner in which the stamens are arranged inside the corolla is shown at (d). The cells of the capsule, when ripe, open down the centre, and the seeds which are angular, are attached to a five-lobed placenta.