A deciduous shrub rarely more than 3 to 4 ft high; branches erect-growing; branchlets glabrous except when quite young. Leaves narrowly oval, tapering about equally to either end; mostly 2 to 21⁄2 in. long, 1⁄2 to 3⁄4 in. wide, with scattered bristles on the upper surface and margins, lower surface downy, becoming, in some plants at least, nearly or quite glabrous before falling. Flowers bright rosy purple, 1 to 11⁄2 in. wide, produced in April in a cluster of about six at the end of naked twigs. The corolla has its three upper lobes united almost to the end, and erect; the two lower ones narrow-oblong, divided to the base, and spreading. Calyx green, the lobes shallow, rounded, glandular at the margins; flower-stalks 1⁄4 in. long, glandular: stamens ten, downy quite at the base; anthers purple. Bot. Mag., t. 474. (s. Azalea ss. Canadense)
Native of eastern N. America; introduced in 1767. This is one of the brightest and most pleasing of early-flowering shrubs, and one of the hardiest. Once considered distinct enough to constitute a separate genus (Rhodora), it was later united with Rhododendron. But from all the deciduous species, the curious two-lipped corolla consisting of one broad, erect segment and two spreading narrow ones, and (from most) the ten stamens distinguish it. The twigs of the year are remarkable also in thickening gradually towards the end. Increased by seed. Often growing in swamps in the wild, it loves a moist position under cultivation.