An evergreen shrub up to 6 ft high in the wild. Leaves thinly leathery, oblong-elliptic to oblong-obovate, rounded at the apex, up to 27⁄8 in. long and 1 in. wide, glabrous above when mature, underside clad with a 'very thin discontinuous mealy indumentum composed of branched or star-like hairs . . . scattered over the undersurface of the leaf. At the same time the undersurface of the leaf is very minutely papillate and has a greenish brown appearance' (Cowan, Notes R.B.G. Edin., Vol. 20, p. 77). Inflorescence a terminal umbel of three to six flowers, opening in April or May (later in some forms). Calyx fleshy at the base, up to 1⁄4 in. deep. Corolla tubular-campanulate, 11⁄2 in. long, crimson or pink. Stamens downy at the base. Ovary tomentose and glandular; style glabrous. (s. Neriiflorum ss. Sanguineum)
R. eudoxum is a native of N.W. Yunnan and bordering parts of Tibet (Tsarong) on the Mekong-Salween and Salween-Irrawaddy divides and was introduced by Forrest. It received an Award of Merit when shown by E. H. M. and P. A. Cox on April 26, 1960 (a form with flowers of the shade of pink known as Solferino Purple, with a deeper crimson tinge at the base).
subsp. brunneifolium (Balf. f. & Forr.) Cowan R. brunneifolium Balf. f. & Forr. – Differing from the typical state mainly in having the ovary eglandular.
R. fulvastrum Balf. f. & Forr. – Leaves with a thin indumentum beneath (not continuous and plastered as in R. sanguineum), but differing from R. eudoxum in that the indumentum is cobwebby, not mealy as in that species, and is made up of scattered, long-branched hairs (Cowan). Ovary tomentose, eglandular. Flowers typically pale yellow, but rose, pink, or yellowish red in subsp. meso-polium (Balf. f. & Forr.) Cowan.
From the Supplement (Vol. V)
The Edinburgh revision recognises only three varieties, not subspecies, here:
var. eudoxum. – The typical variety with a mainly glandular ovary.
var. brunneifolium (Balf.f. & Forr.) Chamberlain – Leaves 23⁄4 to 31⁄2 in. long; indumentum brownish. Ovary mainly tomentose.
var. mesopolium (Balf.f. & Forr.) Chamberlain – Leaves 13⁄8 to 31⁄2 in. long; indumentum whitish. Ovary mainly tomentose.
For synonymy, see Rev. 2, pp. 401-3.