An evergreen bush 5 to 10 ft high; young shoots purplish, they and flower-stalks glandular and viscid. Leaves 2 to 31⁄2 in long, 1 to 2 in. wide; broadly ovate, with a heart-shaped or truncate base and a blunt, glandular tip, of a distinct glaucous, somewhat metallic hue, quite glabrous on both surfaces; stalk glandular when young, 1⁄2 to 3⁄4 in. long. Flowers in a terminal cluster, about six in each, opening in May; pedicels 11⁄2 to 2 in. long. Calyx up to 1⁄4 in. long, glandular at least on the margins of the lobes, sometimes throughout. Corolla very open and saucer-shaped, five- or six-lobed, soft rosy pink or white flushed with pink, 2 to 3 in. across. Stamens eight or ten. Ovary glandular; style glandular to the tip. Bot. Mag., t. 8622. (s. Thomsonii ss. Souliei)
Native of W. Szechwan; discovered by the French missionary Soulié near Kangting (Tatsienlu) and introduced by Wilson in 1903 when collecting for Messrs Veitch and also cultivated from the seeds he sent a few years later, during his first expedition for the Arnold Arboretum. Some of the plants raised at Kew flowered when only four years old. It is a very hardy rhododendron, best planted in open woodland or slight shade, as it needs plenty of light if it is to flower freely. It is also one of the most beautiful, with flowers of exquisite shape and colouring set off by foliage of a rich sea-green. It has been awarded a First Class Certificate on three occasions. The first went to a plant 9 in. high, shown by Messrs Veitch on May 18, 1909; flowers bright rose suffused on a paler ground. The second was given to a form with flowers of a deeper pink, shown from Exbury on May 19, 1936, under the name ‘Exbury Pink’. The third award was to ‘Windsor Park’, shown by the Crown Estate Commissioners, Windsor Great Park, on May 22, 1951; truss of nine flowers, white with a pink flush deepening at the margins, and with a small crimson blotch at the base of the three upper lobes.
R. puralbum Balf. f. & W. W. Sm. – Flowers pure white, otherwise not differing botanically from R. souliei. It was introduced by Forrest in 1913 from the mountains in the north-east of the Yangtse bend, and was discovered by him. A plant from the original introduction (F. 10616) flowers freely in the Edinburgh Botanic Garden, but the species is rare in gardens.