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 temenium' from the website Trees and Shrubs Online (treesandshrubsonline.
Dwarf shrub, 0.3-1.5 m. Leaves 3.5-5(-8) x 1.2(-3) cm, elliptic, lower surface glabrous or with the remains of a whitish floccose indumentum persisting, especially on the midrib and main veins, lower epidermis glaucous-papillate; petioles tomentose, usually also setose. Flowers 2-6, in a lax to dense truss; calyx 2-5 mm; corolla fleshy, white to pink or carmine, or yellow, campanulate to tubular-campanulate, 35-45 mm; with nectar pouches; ovary tomentose, sometimes also with a few glands, abruptly contracted into the style. Flowering April-May. Royal Horticultural Society (1997)
Distribution China Border of Yunnan & Tibet
Habitat (3,650-)4,250-4,550 m
RHS Hardiness Rating H5
Conservation status Vulnerable (VU)
A shrub 2 to 5 ft high in the wild; young stems usually more or less covered with bristly hairs. Leaves short-stalked or almost sessile, oblong or oblong-elliptic or oblong-obovate, 11⁄4 to 3 in. long, 3⁄4 to 1 in. wide, rounded and mucronate at the apex, rounded or broad-cuneate at the base, of leathery texture, almost glabrous above, undersides papillose, glabrous on mature leaves except for a few floccose hairs. Flowers in terminal clusters of four to six, opening in April or May. Calyx variable in size, sometimes rim-like, sometimes 3⁄8 in. long, coloured like the corolla, which is in some shade of red, fleshy, tubular-campanulate, 11⁄4 to 11⁄2 in. long, five-lobed. Ovary tomentose and glandular. (s. Neriiflorum ss. Sanguineum)
Like other members of the confusing R. sanguineum complex, R. temenium is a native mainly of the Salween-Kiuchiang and Salween-Mekong divides in the Tibetan region of Tsarong and bordering parts of Yunnan. It resembles R. aperantum in the glabrous and papillose undersurface of the leaves, but that species is nearly always of dwarf habit, the stems are not bristly, and the leaf-bud scales are persistent (deciduous in R. temenium). It comes from alpine elevations and makes a compact, hardy bush.
subsp. albipetalum Cowan – Flowers white. Introduced by Rock.
subsp. chrysanthemum Cowan – Flowers yellow. Ovary tomentose, but not glandular. Introduced by Rock. The clone ‘Cruachan’, raised from his no. 22272, received an Award of Merit on April 22, 1958, and a First Class Certificate in 1964, on both occasions when shown by Mrs K. L. Kenneth, Tich-an- Rudha, Ardrishaig; the flowers are sulphur-yellow. The original plant has since died. The subsp. gilvum Cowan is similar, but the ovary is glandular.
subsp. glaphyrum (Balf. f. & Forr.) Cowan R. glaphyrum Balf. f. & Forr. – Flowers cream or rose or a blend of the two. Ovary eglandular. Introduced by Forrest.
subsp. pothinum (Balf. f. & Forr.) Cowan R. pothinum Balf. f & Forr. – Like typical R. temenium, but with the ovary devoid of glands. Introduced by Forrest.
A simplified treatment of this species is provided in Rev. 2, pp. 404-5.
var. temenium R. pothinum Balf.f. & Forr. R. temenium subsp. pothinum (Balf.f. & Forr.) Cowan – Young shoots and pedicels bristly. Flowers carmine to crimson.
var. dealbatum (Cowan) Chamberlain, including R.t. subsp. glaphyrum Cowan – Flowers white to deep pink. Inflorescence lax. Bristles weakly developed.
var. gilvum (Cowan) Chamberlain, including R.t. subsp. chrysanthemum Cowan – Flowers yellow. Otherwise as in var. temenium.
R. glaphyrum Balf.f. & Forrest
Corolla white to deep rose-pink; inflorescence lax; young shoots and pedicels weakly setose, occasionally lacking setae. Royal Horticultural Society (1997)
This species is closely allied to R. eudoxum and to R. sanguineum, and almost certainly hybridizes with both. R. temenium may also hybridize with R. citriniflorum and R. catacosmum. Royal Horticultural Society (1997)
R. temenium Balf.f. & Forrest subsp. chrysanthum Cowan
Corolla yellow, otherwise as for var. temenium. Royal Horticultural Society (1997)
AM 1958 amd FCC 1964 (Mrs K.L. Kenneth, Ardrishaig) to a clone 'Cruachan', as R. temenium var. chrysanthum; flowers Sulphur Yellow.
Corolla carmine to crimson; inflorescence dense; young shoots and pedicels always setose, usually strongly so.