An evergreen shrub 3 to 7 ft high, of loose habit; young shoots reddish, slender, scaly. Leaves lanceolate, with a long slender point and a tapered base, 11⁄2 to 31⁄2 in. long, 1⁄2 to 11⁄4 in. wide; dark green above, paler and more scaly beneath; stalk 1⁄4 to 1⁄3 in. long. Flowers pale yellow, produced singly or occasionally in pairs from several buds at the apex of the shoot, terminal and axillary. Calyx scarcely lobed. Corolla broadly funnel-shaped, 1 in. wide. Stamens ten, protruded, hairy near the base. Ovary, calyx, and flower-stalk scaly, the last 1⁄2 in. long. Bot. Mag., t. 8851. (s. and ss. Triflorum)
Native of W. Szechwan and N.E. Yunnan, mainly at altitudes of 6,500 to 9,500 ft; discovered by the Abbé David; introduced by Wilson in 1904 for Messrs Veitch and again during his two expeditions on behalf of the Arnold Arboretum. According to him it is very common in thickets and margins of woods fully exposed to the sun, and is one of the earliest rhododendrons in its area to open its flowers. It is the finest yellow-flowered species in the Triflorum series but unfortunately in cultivation too it is early-flowering, sometimes as early as February and never later than April, so its display is often spoilt by frost. Also, some plants are somewhat tender, though it is said that Wilson's later introductions are hardier than the first. The bronzy young growths are an attractive feature of this species.
The well-known Exbury variety of R. lutescens, with large lemon-yellow flowers, was the result of deliberate crossing between two selected plants. It was awarded a First Class Certificate when exhibited by Lionel de Rothschild on March 22, 1938. An Award of Merit was given on March 31, 1953, to the clone 'Bagshot Sands', raised at Tower Court and exhibited by Mrs Stevenson; in this the flowers are primrose-yellow and about 11⁄2 in. wide.