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.
The Strawberry tree (Arbutus Unedo) has little bell-shaped flowers, contracted at the mouth, and with a curling-back limb, which are easily recognised as belonging to the Ericaceæ. They have ten stamens, the filaments of which are hairy at the base (see a in fig. 55) and
Fig. 55.—Fruit &c. of Arbutus Unedo. inserted in the disk; which in this genus is large, and rises up round the ovary (see b). The calyx is permanent, and five-cleft; and the flowers are produced in panicles, and each is furnished with a bract. The fruit, which retains the calyx when ripe, is a granular berry, covered with tubercles on the outside; and it has five cells (c) containing the seeds. There are numerous varieties of this species common in British gardens, besides a very beautiful hybrid between it and A. Andrachne. The latter species is a native of Greece, and rather more tender than the common kind; and it is very conspicuous in shrubberies from its red stems and loose bark.
The Bearberry (Arctostaphylos Uva-Ursi) was formerly considered to belong to the genus Arbutus, but it differs in the filaments of the stamens being smooth and dilated at the base, and the awns affixed to the middle of the anthers. The berry is without tubercles, and the cells are often only one-seeded.