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 racemosum' from the website Trees and Shrubs Online (treesandshrubsonline.
Small shrub, 0.2–3 m; young shoots scaly, glabrous or finely puberulent. Leaves 1.5–5 × 0.7–3 cm, broadly obovate to oblong-elliptic, apex usually rounded and mucronate, upper surface with a few filiform hairs overlying the midrib, otherwise glabrous, lower surface with epidermis white-papillose, densely covered with rimless scales, glabrous. Flowers 2–3, in a loose axillary terminal inflorescence; calyx rim-like, not ciliate; corolla pale to deep pink, occasionally white, openly funnel-shaped, 7–17 mm; stamens 10; ovary densely scaly, glabrous, impressed below the declinate, glabrous style. Flowering March-May. Royal Horticultural Society (1997).
Distribution Yunnan, SW Sichuan, Guizhou
Habitat (800–)2,750–4,300 m
RHS Hardiness Rating H6
Awards AM 1970 (Hydon Nurseries, Godalming) to a clone 'Rock Rose', from Rock 11265 (USDA 59578); flowers red-purple. AM 1974 (Glendoick Gardens, Perth) to a clone 'White Lace'; flowers white. FCC 1892 (J. Veitch and Sons, Chelsea). AGM 1993, to a clone 'Rock Rose'.
Conservation status Least concern (LC)
Taxonomic note This is a common species with distinctive leaves. Royal Horticultural Society (1997).
An evergreen species varying in habit from a dwarf compact shrublet to a tall, straggly bush; young stems scaly, usually deep red, glabrous or slightly downy, never bristly. Leaves up to 2 in. long and 1 in. wide, oval, elliptic, oblong, or broadest slightly above or below the middle, usually rounded or obtuse at the apex, upper surface dull or glossy, with or without scales, underside glaucous and scaly, both sides glabrous or almost so; petiole very short. Flowers produced in April or May from axillary inflorescence-buds, which may be concentrated near the apex of the shoot or more widely spread along it; individual clusters with one to six flowers; pedicels up to 5⁄8 in. long. Calyx very small. Corolla widely funnel-shaped, pale to deep pink or rose-coloured, about 1 in. wide, the tube shorter than the lobes. Stamens ten, usually downy at the base. Ovary scaly; style usually longer than the stamens, glabrous, or downy at the base. Bot. Mag., t. 7301. (s. Scabrifolium)
Native of W. China, common in the drier parts of Yunnan, found at 9,000 to 14,000 ft in open places or as undergrowth in oak or pine woodland. It was first raised in the Jardin des Plantes, Paris, in 1889, and was introduced to Kew in November of that year. The seed had been gathered and sent to Paris by its discoverer, Père Delavay. R. racemosum soon spread into gardens and was awarded a First Class Certificate as early as 1892. But the present garden stock mainly derives from later sendings by Forrest, Kingdon Ward, and Rock.
R. racemosum is one of the most distinct and pretty of the dwarfer rhododendrons. Its most remarkable feature, which it shares with other members of the Scabrifolium series, is the production of flowers from the leaf-axils along the previous year’s wood. Often from six to more than twelve inches of the shoot will be laden with blossom – very different from the single truss which in Rhododendron is usually seen terminating the shoot. On vigorous garden seedlings the season’s growths are sometimes compound, consisting of the main shoot and several short laterals on which inflorescence-buds are developed. Another peculiarity of some garden plants is that a proportion of the inflorescence-buds abort and turn grey.
The flowers of R. racemosum vary much in depth of colour, but in a large group raised from seed – and few rhododendrons can be more easily or quickly raised by this means – the paler-coloured plants serve as a foil to those with flowers of a richer colour, and the total effect is delightful. But if there is room for only one or a few plants, a selection raised from cuttings is preferable.
A very dwarf and compact form of the species, with flowers of a deep cerise pink, was sent by Forrest in 1921 from the Sungkwei pass, Yunnan, under number F. 19404 – ‘the finest form I have yet seen’ he added in his field notes. The true form is available in commerce, but some plants sent out as R. racemosum F.19404 are evidently seedlings taken from open-pollinated plants, and are quite worthless.
A tall-growing clone with deep pink flowers in large rounded clusters, distributed by Glendoick Gardens Ltd, Perth. The leaves are less waxy on the underside than in many other clones.
Flowers bright pink. Habit erect, to 4 or 5 ft. Award of Merit April 28, 1970, when shown by the Hydon Nurseries. The original plant was raised at Tower Court from Rock 59578.There is also a white-flowered form in cultivation.