A dwarf bush of neat, rounded habit, up to 4 or 5 ft high, with glabrous branches. Leaves ovate-lanceolate, 1 to 21⁄2 in. long, 3⁄4 to 1 in. wide; more or less drawn out at the apex, finely toothed, almost or quite glabrous; stalk 1⁄4 in. or less long; stipules linear, with gland-tipped teeth. Flowers white or rosy, scarcely 1⁄2 in. across, on stalks 1⁄4 in. long, produced in April. Fruits scarcely 1⁄2 in. in diameter, red, making a bright display when freely borne. Bot. Mag., t. 8260.
Native of N. China, Korea, and the southern part of the Ussuri region; described from Japan, but not native there. It is best known in its two double-flowered garden varieties (see below).
The single-flowered type appears to have been cultivated in Britain in Loudon’s time as “Cerasus japonica”, but it disappeared from gardens and was not introduced until late in the 19th century. It is allied to P. humilis (q.v.).
Of the double-flowered varieties of P. glandulosa there are two: ‘Alba Plena’, with white flowers, and ‘Rosea Plena’ (syn. ‘Sinensis’), with pink flowers. They provide a remarkable illustration of how much the flowers of a plant can be improved by cultivation. The typical plant in flower is a pretty but by no means striking shrub, whereas the double varieties are amongst the very élite of their class. The flowers carry numerous petals, and are 1 to 11⁄4 in. in diameter, and their stalks become 3⁄4 in. or more long. The foliage too, is finer, the leaves measuring 3 to 4 in. in length by 1 in. in width. They flower in early May, later than the type. The double varieties have been cultivated, and brought to their present perfection, in China and Japan. The rosy-coloured one was introduced in the second half of the 17th century.
The double-flowered varieties were at one time used for forcing early into bloom under glass. Out-of-doors they are seen to best advantage planted against a south wall, where the flowering shoots should be pruned back almost to the older wood as soon as ever the flowers are faded. But they are also very delightful in the open ground but are more subject to die-back grown in this way. They can be propagated by cuttings, but layers prove more satisfactory as a rule. Both have received an Award of Merit.
P. japonica Thunb. – This shrub is allied to P.glandulosa but differs in its ovate, acuminate, sharply double-toothed leaves. It is a native of China but named from a Japanese garden plant. A form with pink, semi-double flowers was in cultivation early in the 19th century and is figured in Bot. Mag., t. 2176, and Bot. Reg., t. 27. It was found more difficult to cultivate than P. glandulosa ‘Rosea Plena’ (‘Sinensis’) and probably soon dropped out of cultivation. The species is more subject to die-back than P. glandulosa in the British climate and no more ornamental (Ingram, Orn. Cherries, p. 175).
In P. japonica var. nakaii (Lévi.) Rehd., the leaves are downy beneath. This was introduced by Wilson from Korea in 1918 (W.10596).