An evergreen shrub 8 to 10 ft high in cultivation and of dense, bushy, very leafy habit; young shoots at first woolly. Leaves oblong, narrowly oval or obovate, rounded or slightly heart-shaped at the base, abruptly narrowed to a short point, 3 to 51⁄2 in. long, 1 to 21⁄2 in. wide, dark green and glabrous above, woolly beneath, but only on the midrib where the wool is dense at the base, fading away upwards until at the upper third it quite disappears; stalk 1⁄2 to 11⁄2 in. long, downy like the base of the midrib. Flowers opening in March and April in loose trusses 4 in. wide composed of six to ten blossoms, on woolly stalks up to 1 in. long. Calyx small, with five triangular lobes. Corolla five-lobed, bell-shaped, 11⁄2 in. wide, pale rose to white with a dark crimson, almost black spot at the base, to which the specific name refers. Stamens ten, shorter than the corolla, their stalks downy at the base; anthers black or nearly so. Ovary cylindrical, 3⁄16 in. long, covered with short, pale tawny hairs; style glabrous. (s. Barbatum ss. Maculiferum)
Native of W. Hupeh and bordering parts of Szechwan; discovered by Père Farges early in the 1890s and introduced by Wilson, who collected seeds in the Changyang district of W. Hupeh in December 1900 and sent them to Messrs Veitch. According to him, it is a woodland plant in the wild, found in W. Hupeh at higher altitudes than any other rhododendron except R. fargesii (up to 10,000 ft). Normally it is a bushy shrub in the wild, 8 to 15 ft high, but Wilson saw one plant which made a tree about 30 ft high.
R. maculiferum is a well-marked species with its bell-shaped flowers, marked at the base with a dark crimson blotch. In some forms the corolla is pure white and the blotch almost black – a remarkable contrast. It flowers in March and April, not always freely, and is inclined to hide its trusses in the luxuriant foliage. It is quite hardy, but very rare in gardens.