An evergreen shrub up to 6 or 10 ft high; young shoots stout, purplish, glandular. Leaves almost orbicular, but usually somewhat longer than broad, 2 to 4 in. long, deeply auricled at the base, rounded at the apex, with a minute tip formed by a slight prolongation and thickening of the midrib; quite glabrous, dark green above, glaucous beneath; stalk 11⁄2 to 2 in. long, very stout. Flowers borne in April or May, up to ten or so in a terminal truss 6 in. across; flower-stalks glabrous, up to 21⁄4 in. long. Calyx minute, glabrous. Corolla widely bell-shaped, 2 to 21⁄2 in. across, seven-lobed, pale magenta-pink. Stamens about fourteen, shorter than the corolla. Ovary glandular, style glabrous. Bot. Mag., t. 8775. (s. Fortunei ss. Orbiculare)
Native of W. Szechwan, China; discovered by Père David around 1870; introduced to Britain by Wilson in 1904. It is a very distinct rhododendron, making a dense bush of rounded habit if not crowded. But the flowers are usually of a cold shade of bluish pink which is far from attractive. It received an Award of Merit in 1922.
R. cardiobasis Sleum. – Leaves similar in shape to those of R. orbiculare, but cordate (not auricled) at the base, and somewhat larger. It differs markedly from R. orbiculare in having the pedicels and rachis glabrous, and the style (as in ss. Fortunei) glandular to the tip. It was described from a specimen collected in Kwangsi province, S. China, a region remote from the homeland of R. orbiculare.
From the Supplement (Vol. V)
subsp. cardiobasis (Sleumer) Chamberlain R. cardiobasis Sleumer – This is mentioned under R. orbiculare on page 733, as a related species.