An evergreen shrub 3 to 6 ft high, of bushy habit, and usually wider than it is high; young branches, leaves, flower-stalks, and calyx covered with reddish-brown scurf or scales. Leaves oval or oblong, 1 to 3 in. long, 1⁄3 to 3⁄4 in. wide; margins recurved; upper surface dark dull green, lower one glaucous white or sometimes pale brown when young; stalk 1⁄8 to 1⁄3 in. long. The leaf when crushed has a strong, rather resinous odour. Flowers 3⁄4 to 11⁄4 in. wide, rosy red, produced during May in terminal clusters of usually five or six (sometimes eight to ten). Calyx large, with five ovate, pointed lobes, 1⁄3 in. long, scaly outside. Corolla bell-shaped, with five spreading, rounded lobes, slightly scaly outside; Stamens ten, downy at the base. Style straight or bent. Bot. Mag., t. 4721. (s. and ss. Glaucophyllum)
Native of the Himalaya from E. Nepal eastward at 10,000 to 12,000 ft; introduced by J. D. Hooker in 1850. It is quite hardy in a sheltered place, and pretty when well in bloom, though not showy. The hybrid 'Rosy Bell' derives from this species.
var. luteiflorum Davidian – Flowers clear yellow. This interesting and attractive variety was discovered by Kingdon Ward and his wife in 1953 during their expedition to the northern part of the Triangle, a region of upper Burma lying between the two main branches of the upper Irrawaddy, the Nmai Hka and the Mali Hka. When he first saw it the flowers were over and he took it to be ordinary R. glaucophyllum. 'My surprise, therefore, was great when the bright November sunshine so warmed the fat winter buds of this little plant that they blurted into brief flower, revealing golden corollas! It was a brighter and better R. brachyanthum' (Return to the Irrawaddy, p. 172). It was introduced by him the same year and was described in 1960.
A First Class Certificate was given in 1966 to a clone of the var. luteiflorum named 'Glen Coy', shown from the Brodick Castle Gardens, Isle of Arran (R.C.Y.B. 1967, Pl. 4).
var. tubiforme Cowan – Corolla tubular, style straight. Introduced by Ludlow and Sherriff from east Bhutan (L. & S. 2856).
From the Supplement (Vol. V)
var. album Davidian – Flowers creamy white. This interesting variant was introduced from east Nepal by the University of North Wales Expedition (B.L. & M. 315). A clone deriving from this sending has been 'Len Beer', named after the leader of the expedition, who died in 1977 at the age of thirty-five (Rhododendrons 1977, pp. 69-70).
var. luteiflorum – See below, as R. luteiflorum.
var. tubiforme – Accepted as a variety in the Edinburgh revision, this has been promoted to species level by Mr Davidian and with good reason. In addition to being very distinct in floral characters it is geographically almost separate from R. glaucophyllum, its known occurrences being confined to eastern Bhutan, the Assam Himalaya and bordering Tibet. R. glaucophyllum proper ranges from Nepal to Bhutan. The type was collected by Kingdon Ward on the Manda La in the Assam Himalaya in 1935. The cultivated plants from the Ludlow and Sherriff introduction grow taller than R. glaucophyllum in gardens.
R. luteiflorum (Davidian) Cullen R. glaucophyllum var. luteiflorum Davidian – Kingdon Ward introduced this from The Triangle of northern Burma under two numbers – KW 21040 abnd KW 21556. Peter Cox reports that plants from the latter are somewhat more compact and hardy than those from the former (The Smaller Rhododendrons, p. 98).