Dwarf shrub, to 1.5 m; shoots with a smooth brown flaking bark. Leaves 3–5.5 × (1.4–)1.8–3 cm, elliptic to obovate, apex bluntly rounded to retuse, lower surface with scales of varying density. Pedicels scaly. Flowers (3–)4–5 per inflorescence; calyx (3–)5–7(–9) mm, ovate, rounded at apex; corolla pink to purplish, sometimes with flecks, campanulate, (15–)20–25 mm; stamens 10, regular; ovary densely scaly, style sharply deflexed, glabrous. Flowering April-May. Royal Horticultural Society (1997).
RHS Hardiness Rating H5
Conservation status Vulnerable (VU)
A dwarf evergreen shrub up to 2 ft high in the wild; young shoots scaly. Leaves obovate, the apex mucronulate, the base wedge-shaped, 1 to 23⁄4 in. long, 1⁄2 to 11⁄8 in. wide, glossy dark green above, pale green and fairly thickly sprinkled over with yellowish shining scales beneath; stalk 1⁄6 in. long. Flowers opening in May, usually three (sometimes two to four) in a terminal cluster, each on its slender scaly stalk which is 3⁄4 to 1 in. long. Calyx large for the size of the flower, 1⁄3 in. long, cut to the base into five ovate lobes, scaly outside. Corolla bell-shaped, five-lobed, about 1 in. wide, clear pink, speckled with crimson. Stamens ten, hairy on the lower two-thirds; ovary densely scaly; style 1⁄3 in. long, thick and glabrous. Bot. Mag., t. 9358. (s. and ss. Glaucophyllum)
Native of N.E. upper Burma, found in the Shing Hong pass by Farrer in June 1920. It was then in flower and he describes it as a ‘particularly charming plant with three- (rarely four-) bloomed inflorescences. Flowers of a clear apple-blossom pink flushed more warmly in the upper lobes, and speckled with crimson; and with a deep rose tube.’ Farrer died before he could harvest the seeds of his 1920 discoveries, but four years later Forrest met with this species near the type-locality and introduced it (F.25570 and 25581).
It is a very attractive little shrub, quite hardy, though its expanding flower-buds may be killed by late frost. Often it produces a quite heavy crop of flowers in the autumn, though at the cost of next spring’s display.
(The authors as above, not as printed on page 628.)
subsp. tsangpoense (Hutch. & Ward) Cullen R. tsangpoense Hutch. & Ward; R. tsangpoense var. curvistylum Cowan & Davidian; R. curvistylum Ward, nom. nud. – This has a more northerly distribution than the typical subspecies. With regard to var. curvistylum (page 629), Dr Cullen remarks that while the (flowering) type-specimen belongs to subsp. tsangpoense, plants cultivated under KW 5843 are of the parentage suggested by Kingdon Ward. This is puzzling, as the collector clearly considered that his flowering specimen (KW 5843) was also hybrid (5844 being R. tsangpoense and 5842 R. campylogynum).
R. pruniflorum Hutch. R. tsangpoense var. pruniflorum (Hutch.) Cowan & Davidian; R. sordidum Hutch. – Dr Cullen restores this rhododendron to its original species status. He considers it to be a very distinct species, more closely related to R. brachyanthum than to R. charitopes, despite the difference in flower colour.
Calyx 6–9mm; corolla pink.
Distribution NE Burma, China (NW Yunnan).
Awards AM 1979 (Crown Estate Commissioners, Windsor) to a clone Tarkside’; flowers in clusters of three, red-purple, with upper lobes suffused with darker shades, upper lobes extensively spotted with red-purple.
R. tsangpoense Kingdon-Ward var. tsangpoense
R. tsangpoense Kingdon-Ward var. curvistylum Kingdon-Ward ex Cowan & Davidian
Calyx (3–)5–6mm; corolla pink or purple.
Distribution China (S Tibet).
Awards AM 1972 (Maj. A.E. Hardy, Sandling Park, Kent) to a clone ‘Cowtye’, probably from Kingdon-Ward 7744; flowers purple, with darker spots and a waxy bloom.
Taxonomic note (R. tsangpoense Kingdon-Ward, & incl. var. curvistylum Kingdon-Ward ex Cowan & Davidian)
There is no clear separation between the two subspecies, the distributions of which do not however overlap.
R. pruniflorum Hutch.
R. sordidum Hutch