Shrub, 2–3 m; young shoots tomentose though soon glabrescent; bud scales deciduous. Leaves 6.5–11.5 × 3.5–5 cm, broadly elliptic to obovate, apex more or less obtuse, upper and lower surfaces glabrous when mature though with persistent hair bases below. Flowers 15–20, in a dense truss; calyx c.1 mm; corolla usually lilac-purple, with faint flecks, funnel-campanulate, nectar pouches lacking, 30–45 mm; ovary densely rufous-tomentose, style glabrous. Flowering May-June. Royal Horticultural Society (1997)
Distribution United States E
Habitat 50–1,000 m
RHS Hardiness Rating H7
Awards AM 1990 (Crown Estate Commissioners, Windsor) to a clone 'Catalgla'; trusses full, 15-20-flowered, corolla white, with some yellow-green spotting in upper throat.
Conservation status Least concern (LC)
Taxonomic note This species differs from the closely allied R. ponticum in its more or less glabrous ovary. It has been used widely as a parent in breeding programmes. Royal Horticultural Society (1997)
An evergreen shrub 6 to 10 ft high, forming eventually a large spreading bush wider than high – a dense thicket of branches and leaves. Leaves oval or oblong, 3 to 6 in. long, 11⁄4 to 2 in. wide, broadest above the middle, dark glossy green above, pale beneath, glabrous on both sides; stalk 1⁄2 to 11⁄4 in. long. Flowers lilac-purple, produced in a large cluster 5 or 6 in. across; corolla 11⁄2 in. long, 21⁄2 in. broad, with five short, rounded spreading lobes; calyx with five shallow, triangular pointed lobes; stamens white, downy at the base; flower-stalks 1 to 11⁄2 in. long, glandular-downy; ovary brown-felted; style red. Bot. Mag., t. 1671. (s. and ss. Ponticum)
Native of the slopes and mountain summits of the south-eastern United States, where it is described as forming dense thickets ‘through which the traveller can only make his way by following old bear tracks’. In the gardens of Britain, to which it was introduced in 1809 by John Fraser, it has proved one of the most valuable evergreen shrubs for ornament ever introduced. In the hands of nurserymen, but chiefly of the Waterers, it has given birth by selection and hybridisation to a most valuable group of evergreen garden rhododendrons – hardy and easily grown – the group which flowers in May and June. The characteristics of this group, as compared with the companion group derived from R. ponticum, are their broad foliage and greater hardiness.