This species seems to be represented in cultivation by the following variety:
var. mollis (Hook.) Brewer & Watson Cerasus mollis Dougl. ex Hook.; C. pattoniana Carr. – A deciduous tree, sometimes 30 to 40 ft high, with a trunk 1 ft or more in diameter; branches downy when young, becoming glabrous with age; bark exceedingly bitter. Leaves obovate-oblong, usually rounded or blunt at the apex, tapering towards the base, 11⁄2 to 21⁄2 in. long, scarcely half as wide, finely and bluntly toothed, downy beneath; stalk about 1⁄4 in. long. Flowers dullish white, not 1⁄2 in. across, produced six to twelve together in May on corymbose clusters 11⁄2 in. long, each flower on a downy stalk 1⁄4 to 1⁄2 in. long; petals notched at the apex; calyx downy, lobes rounded. Fruits 1⁄4 to 1⁄2 in. diameter, red, finally almost black.
A native of British Columbia and Oregon; discovered by David Douglas; introduced to Britain in 1861-2 and at first known in gardens as Cerasus pattoniana – the name under which the seeds were distributed. It is a handsome tree of healthy aspect and of neat habit, but its flowers are not sufficiently pure white to be really effective. The bark, leaves, and fruit are permeated by an intensely bitter principle.
Typical P. emarginata is less downy or almost completely glabrous, and is usually of smaller stature. It has a wider range in western North America than the var. mollis. It, too, was discovered by David Douglas.