Rhododendron temenium Balf. f. & Forr.

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Credits

Article from Bean's Trees and Shrubs Hardy in the British Isles

Recommended citation
'Rhododendron temenium' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-temenium/). Accessed 2024-12-02.

Genus

Other taxa in genus

Glossary

calyx
(pl. calyces) Outer whorl of the perianth. Composed of several sepals.
inflorescence
Flower-bearing part of a plant; arrangement of flowers on the floral axis.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
apex
(pl. apices) Tip. apical At the apex.
bud
Immature shoot protected by scales that develops into leaves and/or flowers.
campanulate
Bell-shaped.
clone
Organism arising via vegetative or asexual reproduction.
corolla
The inner whorl of the perianth. Composed of free or united petals often showy.
cuneate
Wedge-shaped.
glabrous
Lacking hairs smooth. glabrescent Becoming hairless.
glandular
Bearing glands.
lax
Loose or open.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
sessile
Lacking a stem or stalk.

Credits

Article from Bean's Trees and Shrubs Hardy in the British Isles

Recommended citation
'Rhododendron temenium' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-temenium/). Accessed 2024-12-02.

Dwarf shrub, 0.3–1.5 m. Leaves 3.5–5(–8) × 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, 114 to 3 in. long, 34 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 38 in. long, coloured like the corolla, which is in some shade of red, fleshy, tubular-campanulate, 114 to 112 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.

From the Supplement (Vol. V)

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.


var. dealbatum (Cowan) D.F.Chamb.

Synonyms
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)


var. gilvum (Cowan) D.F. Chamb.

Synonyms
R. temenium Balf.f. & Forrest subsp. chrysanthum Cowan

Corolla yellow, otherwise as for var. temenium. Royal Horticultural Society (1997)

Awards
AM 1958 amd FCC 1964 (Mrs K.L. Kenneth, Ardrishaig) to a clone 'Cruachan', as R. temenium var. chrysanthum; flowers Sulphur Yellow.


var. temenium

Corolla carmine to crimson; inflorescence dense; young shoots and pedicels always setose, usually strongly so.