The genus Cerasus is divided into two sections, the first containing those species which have their flowers in bunches, and on long footstalks, as in the common Cherry; and the second those which have their flowers in racemes on short footstalks, as in the Bird-cherry (Cerasus Padus); the Mahaleb, or Bois de Sainte Lucie (Cerasus Mahaleb); the common Laurel (Cerasus Lauro-Cerasus); and the Portugal Laurel (Cerasus lusitanicus). These plants are so different from the common Cherry both in flowers and fruit, as far as can be judged from their general appearance, as scarcely to be recognised; but when closely examined their botanical construction will be found the same. Formerly only two genera were included in this tribe—viz. Amygdalus, which comprised the Peach and Nectarine as well as the Almond; and Prunus, which included the Apricot and the Cherry.
TRIBE V.—POMEÆ.
The common apple (Pyrus Malus) may be considered the type of this tribe, which comprehends not only what we are accustomed to call kerneled fruit, but also the Hawthorn, Cotoneaster, and other ornamental shrubs and low trees. The flower of the apple bears con siderable resemblance to the flowers of the genera already described, but the petals (see a in fig. 27) are oblong, rather than roundish.
Fig. 27.—Fruit and part of the Flower of the Apple.
The calyx (b) is tubular in the lower part, and the limb is divided into five lobes. The receptacle lines the lower part of the calyx, and forms a disk, filling its throat, in which the stamens and petals are inserted. There are five ovaries, the styles of which are for half their length united, leaving the upper part and the stigmas free; and the ovaries themselves, now become cells, are enclosed in a cartilaginous endocarp, which forms what we call the core of the Apple, and which adheres firmly to the tubular part of the calyx. There are two ovules in each cell, placed side by side, but generally only one seed in each becomes perfectly ripe. As the seeds advance, the fleshy tube of the calyx swells out and becomes what we call the apple; while the leafy part or lobes of the limb remain on, and form the eye. Fruit of this kind are called pomes.
