Rhododendron nipponicum Matsum.

A deciduous azalea described as of bushy habit and from 3 to 6 ft high; the stiff young shoots reddish brown and clothed with glandular bristles. Leaves scarcely stalked, obovate, rounded, and often notched at the apex, tapered to the base, 2 to 6 in. long, half as much wide, more or less appressed-bristly above and beneath. Flowers opening about midsummer, six to fifteen in a cluster, the pedicels 1⁄2 to 3⁄4 in. long, sticky with glands. Calyx small, with five ovate, ciliate lobes. Corolla narrowly bell-shaped, scarcely 1 in. long, white with five short, slightly spreading lobes. Stamens ten, unequal in length but all shorter than the corolla, downy below the middle. Ovary glandular-hairy; style glabrous. Bot. Mag., n.s., t. 491. (s. Azalea ss. Nipponicum)

Native of the mountains of Central Japan, where it occurs only in a few localities; discovered in 1883. Its existence in gardens is apparently due to E. H. Wilson, who found it on the hills around Toge in 1914 and sent seeds to the Arnold Arboretum. It first flowered at Kew in June 1921, but this species is no longer there. The blossom is very disappointing, being small and hidden away in the young growths. But in foliage it is one of the finest of azaleas and it takes on brilliant orange and crimson tints in autumn. The bright reddish-brown bark is also pleasing. Botanically it is distinct in having the stamens and style included within the somewhat tubular corolla, which resembles that of Menziesia ciliicalyx in shape.