A deciduous azalea up to 9 ft high in the wild; young shoots glabrous, purplish red, becoming greyish later. Leaves oval, or obovate to oblong; 11⁄2 to 4 in. long, 1⁄2 to 11⁄2 in. wide; green and glabrous on both surfaces except on the midrib which is slightly downy above and very sparingly bristly beneath, margins ciliate; stalk 1⁄8 to 1⁄4 in. long. Flowers produced in July or August in clusters of four or five, on hairy stalks. Calyx very small. Corolla vermilion or orange or in an intermediate shade, or dark red, funnel-shaped, the tube 3⁄4 to 1 in. long, glabrous or nearly so outside, downy inside. Stamens five, 2 to 21⁄2 in. long, the lower half downy; ovary covered with pale bristly not glandular hairs. (s. Azalea ss. Luteum)
Native of Georgia and Alabama; found in shady ravines on the banks of streams; introduced to Britain by Prof. Sargent in 1918. Rehder describes it as the most glabrous of all American azaleas and very distinct in being entirely without glandular pubescence except occasionally on the outside of the corolla lobes.
R. prunifolium is said to make a magnificent display in its native habitat, but in this country it is less remarkable, perhaps because our summers are too cool for it. It is uncommon in gardens, though quite hardy. It received an Award of Merit when shown by the Crown Estate Commissioners, Windsor Great Park, on August 1, 1950 (clone 'Summer Sunset', with vermilion flowers).