A shrub to 20 ft high; branchlets slender, glandular when young, otherwise glabrous. Leaves thinly leathery, oblong-elliptic or broader slightly above the middle, apex obtuse to acute or shortly acuminate, base cuneate, 3 to 5 in. long, 1 to 23⁄4 in. wide, deep matt green above with the main veins slightly impressed, undersurface bright green with scattered, glistening brown dots; petiole about 5⁄8 in. long. Flowers borne in April in loose trusses of twelve to fifteen; rachis about 1 in. long; pedicels 5⁄8 to 7⁄8 in. long, glandular. Calyx very small, glandular at the edge. Corolla five-lobed, widely funnel-shaped to cup-shaped, up to almost 3 in. wide, white sometimes flushed with pink, spotted or unspotted. Ovary conoid, glandular, as is the style throughout. Bot. Mag., n.s., t.385.
Native of Kweichow and western Yunnan; described by Franchet from a specimen collected in the former province. The type of R. laxiflorum, the name under which the species has generally been known in cultivation, came from the Shweli-Salween divide, and the plant figured in the Botanical Magazine was raised from seeds collected in the same area. The species, as known in cultivation, is not so tender as was once supposed, but it breaks into growth early, and the flower-buds too may be killed by late frost. It is the most ornamental species of the subsection, apart from R. irroratum itself and R. aberconwayi.