A deciduous tree, described by Sargent as 40 to 50 ft high, forming a broad, compact, round-topped head; young shoots slightly downy at first, soon glabrous; thorns sturdy, 1⁄3 to 1 in. long. Leaves oval or ovate, 1 to 2 in. long, about half as wide, tapered at the base, shallowly round-toothed, glossy dark green, glabrous except on the upper surface when young. On vigorous barren shoots, the leaves are often of almost triangular shape, and truncate or even heart-shaped at the base, with stipules 1 in. long. Flowers small, the petals turning orange-coloured with age; flower-stalks and outside of calyx glabrous; calyx-lobes not toothed; stamens fifteen to twenty; styles three or five. Fruit roundish, bright blue, covered with a blue-white bloom, 1⁄3 to 1⁄2 in. across.
Native of the southern central United States; introduced in 1900. The most remarkable character of this thorn is the bright blue fruit. It belongs to Sargent’s group Brachyacanthae, to which also belongs:
C. saligna Greene – A native of Colorado, at 6,000-8,000 ft. Its glabrous reddish young shoots are armed with thorns 3⁄4 in. or more long. Fruit globose, shining, 1⁄4 in. across, red, finally blue-black. A tree 20 ft high, with firm-textured, deep green, smooth and glossy leaves up to 2 in. long and 1 in. wide, ovate-lanceolate or oval.