Kindly sponsored by
Peter Norris, enabling the use of The Rhododendron Handbook 1998
Article from Bean's Trees and Shrubs Hardy in the British Isles
'Rhododendron orthocladum' from the website Trees and Shrubs Online (treesandshrubsonline.
Much-branched erect low shrub, to 1.3 m. Leaves 0.8-1.6 x 0.3-0.6 cm, narrowly elliptic to lanceolate, apex obtuse, obscurely mucronate, lower surface covered with more or less touching yellow-brown scales, intermixed with few to many that are dark brown. Flowers (1-)2-5 per inflorescence; calyx 0.5-1.5 mm, lobes rounded to deltoid, unequal; corolla pale to deep lavender-blue to purple or whitish pink, funnel-shaped, 7-14 mm; stamens 8-10, shorter than to equalling corolla; ovary scaly, style short or long, glabrous or sparsely scaly. Flowering April-May. Royal Horticultural Society (1997)
Distribution China N Yunnan, SW Sichuan
Habitat 2,500-4,500 m
RHS Hardiness Rating H5
Conservation status Least concern (LC)
An evergreen shrub of densely twiggy, bushy, shape, 3 to 4 ft high; young shoots very slender, densely scurfy. Leaves narrowly oblong or lanceolate, tapered at both ends; 1⁄3 to 3⁄4 in. long, 1⁄12 to 1⁄5 in. wide; dark slightly glaucous green and scaly above, furnished with glistening yellowish scales beneath, and sometimes with scattered larger brown ones; stalk to 3⁄4 in. long. Flowers two to four closely packed in terminal clusters 1 in. wide. Calyx minute, with small lobes covered thickly with glistening scales like the flower-stalk, which is only 1⁄12 in. long. Corolla pale mauve, 3⁄4 in. wide, with a very short, downy tube, five-lobed, the lobes rounded, ovate, 1⁄4 in. long. Stamens ten, purple, about 1⁄4 in. long, with a tuft of down near the base; anthers red. Ovary scaly; style glabrous, reddish, shorter than, or equalling, the stamens. (s. Lapponicum)
Native of N.W. Yunnan and S.W. Szechwan at alpine elevations, in open pastures, on stony slopes, cliffs, etc., sometimes on limestone; discovered and introduced by Forrest in 1913. This is a pleasing dwarf shrub with some resemblance to R. scintillans, but paler in colour of blossom than is usual in that species, and with a shorter style, which varies in length, but does not usually extend to the level of the anthers. There is also some variation in the density of the scales beneath the leaves; in some forms they almost conceal the surface of the blade, in others they are more widely spaced. It is quite hardy at Kew, grows well, and flowers freely towards the end of April, and is noticeable for its neat habit and rounded shape when young. Eventually it will reach a height of 4 ft, but remains of fairly dense habit; wild plants appear to be mostly quite dwarf.
Corolla blue or purple; style 15-16 mm. Royal Horticultural Society (1997)
Style longer than the stamens, as in R. scintillans, from which this variety can be distinguished by the much closer scales on the leaf-undersides. Introduced by Forrest (F.21988).
R. microleucum Hutch.
Corolla white; style 3.5-5 mm. Only known in cultivation. Royal Horticultural Society (1997)
FCC 1939 (L. de Rothschild, Exbury); flowers white. AGM 1994
This is a variable species; var. microleucum may be no more than an albino form of var. orthocladum. Royal Horticultural Society (1997)
Corolla blue or purple; style 3.5-5 mm. Royal Horticultural Society (1997)