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 rubiginosum' from the website Trees and Shrubs Online (treesandshrubsonline.
Shrub or small tree, to 10 m; young growth purplish, scaly Leaves (4–)6–11.5 × (1.2–)2–4.5 cm, narrowly elliptic to elliptic or lanceolate, apex acute to acuminate, lower surface pale or dark brown as a result of the dense overlapping or touching, unequal scales, the larger of which are usually darker than the smaller. Pedicels scaly. Flowers to 10 per inflorescence; calyx very small; corolla pink, rarely white flushed pink, openly funnel-shaped, (15–)20–30(–38) mm; stamens 10; ovary densely scaly, style declinate, glabrous. Flowering April-May. Royal Horticultural Society (1997)
Distribution Myanmar NE China SE Tibet, Yunnan, SW Sichuan
Habitat 2,500–3,500 m
RHS Hardiness Rating H6
Awards AM 1938 (Capt. A.W.T. Fletcher, Port Talbot, Wales) from Forrest 24535, as R. desquamatum; flowers ranging from pale mauve to reddish mauve, with reddish spots. AM 1960 (Sir Henry Price, Wakehurst, Sussex) to a clone 'Wakehurst'; flowers Mallow Purple with prominent purple spots. This clone may be a hybrid.
Conservation status Least concern (LC)
Taxonomic note A variable and widespread species. Royal Horticultural Society (1997)
A stiff-habited, erect-growing evergreen shrub 6 to 20 ft high, branchlets becoming warty. Leaves 11⁄2 to 31⁄2 in. long, 1⁄2 to 1 in. wide; narrowly oval, tapering gradually to each end, upper surface glabrous, dull green, lower one covered with reddish brown scales; stalk 1⁄4 to 1⁄2 in. long. Flowers in terminal clusters of four to seven, produced in April and May; pedicels scaly, about 1⁄2 in. long. Calyx very small. Corolla 11⁄2 to 2 in. wide, rosy lilac, spotted with maroon on the upper side, the tube funnel-shaped, lobes wavy-margined. Stamens ten, downy towards the base. Ovary densely scaly; style glabrous. Bot. Mag., t. 7621. (s. Heliolepis)
Native of S.W. Szechwan (Muli region), N.W. Yunnan, and bordering parts of S.E. Tibet; introduced to Paris in 1889 by Père Delavay and thence to Britain. It is also cultivated from seeds sent later by Forrest and Rock. It is a somewhat stiff, dull-foliaged shrub but is very free-flowering. Its nearest ally is R. desquamatum, but that species has the leaves broadest below the middle and the scales on the undersides of the leaves are unequal, some being larger and darker than others, whereas in R. rubiginosum they are uniform.
R. rubiginosum, in the form originally introduced, was slightly tender at Kew, but the later introductions are usually reckoned to be perfectly hardy. The Award of Merit was given on May 3, 1960, to the clone ‘Wakehurst’, with Mallow Purple flowers, borne from axillary as well as terminal buds, forming clusters of up to twenty-five.
This, not unexpectedly, now includes R. desquamatum in synonymy. The best forms raised from seed-collections previously identified as R. desquamatum could be distinguished as Desquamatum group.