An evergreen shrub about 2 ft high, of rounded, bushy habit, branches densely scaly. Leaves leathery, ovate-oblong, 1⁄2 to 1 in. long, 1⁄4 to 3⁄8 in. wide; rounded at the base, dark green above, paler beneath, scaly on both surfaces; stalk 1⁄/6 in. long. Flowers 1 to 11⁄4 in. across, primrose-yellow, becoming paler with age, produced during April in a terminal cluster of three to six. Corolla with a very short, rather downy tube, and flat, spreading, rounded lobes, wavy at the margins. Calyx pale green, the five lobes oblong, 1⁄4 in. long, covered like the flower-stalk (which is 1⁄8 in. long) with transparent yellowish scales. Bot. Mag., t. 8326. (s. Lapponicum)
Native of W. Szechwan, China; introduced to cultivation by Wilson for Messrs Veitch in 1905. This delightful little species is very distinct through the clear pale yellow of its flowers, and is a valuable acquisition for the rock garden or some place where dainty little plants can grow without danger of being overrun by stronger neighbours. The leaves when crushed have a pleasant, aromatic odour.
The plant known in gardens as R. flavidum album is very distinct in its taller growth, larger leaves and larger, white flowers. Probably a hybrid. In cultivation by 1925.
From the Supplement (Vol. V)
R. psilostylum, given as a synonym, is recognised as a variety – var. psilostylum Rehd. & Wils. (R. psilostylum (Rehd. & Wils.) Balf.f.). It is known from a single collection and is not in cultivation.