A deciduous azalea 3 to 9 ft high; young shoots downy and usually sparingly bristly. Leaves dull or bluish green, oval to obovate, 11⁄2 to 21⁄2 in. long, slightly downy above, densely grey-woolly beneath; margins ciliate. Flowers fragrant, produced during May in clusters of five to nine. Calyx and flower-stalk downy. Corolla bright pink, with a cylindrical tube 3⁄4 in. long, covered outside with thin down and gland-tipped hairs, and with five ovate abruptly pointed lobes. Stamens five, 11⁄2 in. long, downy below the middle; ovary covered with pale silky down; style overtopping the stamens, downy towards the base. (s. Azalea ss. Luteum)
Native of eastern N. America; probably introduced early in the 19th century or even earlier as it grows in the older settled States, but always much confused with R. periclymenoides and R. canescens. To the former it is closely related, but Rehder distinguishes it by its 'pubescent winter-buds and pubescent bluish green leaves, shorter stamens and more or less glandular corolla with larger broader lobes and wider tube'. Being found wild in the States of New York, Massachusetts, etc., this azalea is quite hardy and was once grown under Sweet's name given above. Seeds of this species were sent to England by Sargent in 1922. It is found on limestone in the New York State.
R. prinophyllum received an Award of Merit when shown by Mrs Stevenson, Tower Court, Ascot, on May 24, 1955.