Rhododendron callimorphum Balf. f. & W. W. Sm.

An evergreen shrub up to 9 ft high in the wild, forming a rounded bush in cultivation as wide as it is high; young shoots usually clothed at first with stalked glands. Leaves round to roundish ovate, the base truncate, rounded or heart-shaped, the apex with a short mucro, 1 to 3 in. long, usually not quite so wide, dark glossy green and with scattered hairs above, glaucous beneath with glands on the midrib and margin; stalk 3⁄8 to 1 in. long, usually very glandular. Flowers opening during April and May in a terminal truss of five to eight flowers. Calyx very small with shallow triangular lobes, glandular like the flower-stalk which is 3⁄4 in. long. Corolla openly bell-shaped, five-lobed, 11⁄2 in. long and wide, pale or deep rose with a blotch of intense crimson at the base, lobes notched. Stamens ten, their white stalks from 1⁄2 to 1 in. long, glabrous except for (occasionally) a few minute hairs at the base; anthers brown. Ovary covered with red glands, of which a few extend a short way up the style. Bot. Mag., t. 8789. (s. Thomsonii ss. Campylocarpum)

Native of W. Yunnan and N.E. upper Burma; found by Forrest on the Shweli-Salween divide and introduced by him in 1912; later sendings are from farther north on the E. Irrawaddy-Salween divide and the Tali range. R. callimorphum is a very pretty species of neat habit. It is variable in flowering-time, which is mid- to late May or even early June in some forms. It is hardy at Kew when given a sheltered place and some shade.

From the Supplement (Vol. V)

var. myiagrum (Balf. f. & Forr.) Chamberlain R. myiagrum Balf.f. & Forr. – This differs from typical R. callimorphum only in its white flowers. Stalked glands on the pedicels are also a feature of typical R. callimorphum.