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 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 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. [Illustration: FIG. 53.—LEAF AND ANTHER OF CASSANDRA.] [Illustration: FIG. 54.—FLOWERS, COROLLA, AND STAMEN OF ZENOBIA.] Lyonia is a genus established by the American botanist Nuttall, because the plants it contains have the margins of the valves of their capsules closed by five other narrow external valves. The plants are natives of North America, and their flowers are generally small. _Lyonia Mariana_ may serve as an example of this genus, which is generally adopted by botanists. It would be useless to enter into details of the other genera formed out of Andromeda, as they are not generally adopted; but, perhaps, it may be worth mentioning, that the well-known _Andromeda floribunda_ is placed by Professor Don in a new genus which he calls Leucothoe. St. Dabeoc’s Heath, or Irish Whorts, a little heath-like shrub, common in Ireland, is one of those plants which have puzzled botanists exceedingly. It has been called successively _Erica_, _Andromeda_, and _Menziesia_, _Dabœcia_; then _Erica Hibernica_, next _Menziesia polifolia_, then _Vaccinium Cantabrieum_ and lastly _Dabœcia polifolia_. It is probable, however, that it may even yet be doomed to undergo other changes; as, from the construction of its anthers, which are linear, and arrow-shaped at the base, and which open lengthways, instead of by pores, it does not appear even to belong to the Ericaceæ. The other genera in this sub-tribe are quite distinct from each other, and contain several well-known plants. The most popular of these genera are Arbutus, Arctostaphylos, Gaultheria, and Clethra.