A deciduous tree 15 to 20 ft high, with glabrous, lustrous, reddish young branchlets. Leaves 1 to 2 in. long, one-third as wide, oval-lanceolate, pointed, sharply toothed, tapering at the base to a reddish stalk 1⁄4 to 1⁄2 in. long. Flowers white, 1⁄2 in. across, in clusters of two to four; calyx glabrous outside. Fruits bright red and shining, 1⁄2 in. across, round or nearly so.
A native of eastern North America from New Jersey to Florida and Texas, and west into the Mississippi basin. In the var. varians Wight and Hedrick the leaves are somewhat larger, the flower-stalks longer and the stone pointed at the apex. This and the typical variety are the source of several varieties of plums cultivated in the southern States. Several times introduced to Kew, it never thrives, and it is probably only adapted for the warmest parts of the British Isles, and unless it bears fruits it is scarcely ornamental enough to be worthy of cultivation there. Its close ally, P. watsonii, is better worth growing. The P. chicasa of Michaux, usually regarded as synonymous with P. angustifolia, is said by Hedrick to be different.
P. watsonii Sarg. P. angustifolia var. watsonii (Sarg.) Waugh Sand Plum – A deciduous shrub or small tree 6 to 12 ft high, with glabrous, reddish branchlets. Leaves ovate, pointed, decurved, 1 to 13⁄4 in. long, 1⁄2 to 3⁄4 in. wide, shallowly round-toothed, dark shining green above, paler below, quite glabrous on both surfaces; stalk 1⁄4 to 1⁄3 in. long, grooved, with two glands near the base of the blade. Flowers white, 1⁄2 in. in diameter, produced in clusters of three or four, each on a slender stalk 1⁄4 in. long. Fruits round, orange-red, 3⁄4 in. in diameter, the stone deeply pitted.
Native of the central United States, where it is said to form thickets in low, sandy places near streams. It was first recognised as a distinct species by Sargent in 1894, having previously been confused with P. angustifolia, from which is differs in its ‘thicker leaves, thicker skinned fruit, and smaller more deeply pitted stone’. It is very distinct from P. angustifolia in its behaviour under cultivation, thriving well where that species is a total failure. Introduced to Kew in 1897, but unfortunately it is no longer represented there. It flowers in late April and May, but is not one of the most effective plums in this country.