P. CERASUS (syn Cerasus vulgaris).—­Common Cherry.  A favourite medium-sized tree, and one that lends itself readily to cultivation.  As an ornamental park tree this Cherry, though common, must not be despised, for during summer, when laden with its pure white flowers, or again in autumn when myriads of the black, shining fruits hang in clusters from its branches, it will be readily admitted that few trees have a more beautiful or conspicuous appearance, P. Cerasus flore-pleno (double-flowered Cherry) is a distinct and desirable variety.  P. Cerasus multiplex is a very showy double form, more ornamental than P. Avium muliplex, and also known under the names of Cerasus ranunculiflora and C.  Caproniana multiplex.  P. Cerasus semperflorens (syn Cerasus semperflorens), the All Saints, Ever Flowering, or Weeping, Cherry, is another valuable variety, of low growth, and with gracefully drooping branches, particularly when the tree is old.  It is a very desirable lawn tree, and flowers at intervals during the summer.

P. CHAMAECERASUS (syn Cerasus Chamaecerasus).—­Ground Cherry.  Europe, 1597.  This is a dwarf, slender-branched, and gracefully pendent shrub, of free growth, undoubted hardihood, and well worthy of extended cultivation.  The variety C. Chamaecerasus variegata has the leaves suffused with greenish lemon.  There is also a creeping form named P. Chamaecerasus pendula.

P. DAVIDIANA.—­AbbE David’s Almond.  China.  This is the tree to which, under the name of Amygdalus Davidiana alba, a First-class Certificate was awarded in 1892 by the Royal Horticultural Society.  The typical species is a native of China, from whence it was introduced several years ago, but it is still far from common.  It is the earliest of the Almonds to unfold its white flowers, for in mild winters some of them expand before the end of January; but March, about the first week, it is at its best.  It is of more slender growth than the common Almond, and the flowers, which are individually smaller, are borne in great profusion along the shoots of the preceding year, so that a specimen, when in full flower, is quite one mass of bloom.  There is a rosy-tinted form known as Amygdalus Davidiana rubra.

P. DIVARICATA, from the Caucasus (1822), is useful on account of the pure white flowers being produced early in the year, and before the leaves.  It has a graceful, easy habit of growth, and inclined to spread, and makes a neat lawn or park specimen.

P. DOMESTICA, Common Garden Plum, and P. domestica insititia, Bullace Plum, are both very ornamental-flowering species, and some of the varieties are even more desirable than the parent plants.

P. ILLICIFOLIA (syn Cerasus ilicifolius).—­Holly-leaved Cherry.  California.  A distinct evergreen species, with thick leathery leaves, and erect racemes of small white flowers.  A native of dry hilly ground along the coast from San Francisco to San Diego.  Hardy in most situations, but requiring light warm soil and a dry situation.