Rhododendron coelicum Balf. f. & Farrer

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Credits

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

Recommended citation
'Rhododendron coelicum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-coelicum/). Accessed 2024-03-18.

Genus

Infraspecifics

Other taxa in genus

Glossary

calyx
(pl. calyces) Outer whorl of the perianth. Composed of several sepals.
corolla
The inner whorl of the perianth. Composed of free or united petals often showy.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
petiole
Leaf stalk.
Tibet
Traditional English name for the formerly independent state known to its people as Bod now the Tibet (Xizang) Autonomous Region of the People’s Republic of China. The name Xizang is used in lists of Chinese provinces.
apex
(pl. apices) Tip. apical At the apex.
campanulate
Bell-shaped.
glabrous
Lacking hairs smooth. glabrescent Becoming hairless.
glandular
Bearing glands.
hybrid
Plant originating from the cross-fertilisation of genetically distinct individuals (e.g. two species or two subspecies).
indumentum
A covering of hairs or scales.
inflorescence
Flower-bearing part of a plant; arrangement of flowers on the floral axis.
lax
Loose or open.
midrib
midveinCentral and principal vein in a leaf.
obtuse
Blunt.
style
Generally an elongated structure arising from the ovary bearing the stigma at its tip.

Credits

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

Recommended citation
'Rhododendron coelicum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-coelicum/). Accessed 2024-03-18.

Shrub, 1.3–3 m. Leaves 8–10 × 4.2–5.5 cm, obovate; lower surface covered with a fulvous tomentum, composed of dendroid hairs; petioles sparsely covered with shortly stalked glands. Flowers c.10, in a tight truss; calyx 5–7 mm; corolla fleshy, crimson, tubular-campanulate, with nectar pouches, 38–45 mm; ovary covered with shortly stalked glands, abruptly contracted into the glabrous style. Flowering April-May. Royal Horticultural Society (1997)

Distribution  Myanmar NE China W Yunnan

Habitat 2,750–4,400 m

RHS Hardiness Rating H6

Awards AM 1955 (Col Lord Digby, Minterne, Dorset); flowers a dark shade of Orient Red.

Conservation status Vulnerable (VU)

Taxonomic note Closely allied to R. pocophorum but differing in its broader leaves and non-tomentose petioles. Royal Horticultural Society (1997)

An evergreen shrub up to 6 ft high in the wild; young stems glabrous, not glandular. Leaves leathery, obovate, about 3 in. long, 158 in. wide, rounded and mucronate at the apex, obtuse at the base, glabrous above, clad beneath with a dense cinnamon-coloured indumentum which conceals the lateral veins but not the midrib. Petiole about 38 in. long. Flowers borne March or early April, up to fifteen together in a compact truss on glandular stalks about 38 in. long. Calyx cup-shaped, fleshy, about 14 in. long, with five irregular lobes. Corolla tubular-campanulate, scarlet or crimson, about 112 in. long. Ovary glandular and tomentose; style glabrous. (s. Neriiflorum ss. Haematodes)

R. coelicum was discovered by Farrer on the Chawchi pass, upper Burma, between the Salween and the upper Irrawaddy (Nmai Hka). He described it as a thin, low little bush, flowering in the snow, and ‘making blots of scarlet, visible for miles.’ It is introduced by Forrest from the Tsarong region of S.E. Tibet, some way to the north of the type-locality, growing at 13,000 to 14,000 ft and making a shrub 4 to 5 ft high (F.21830). It belongs to the same subgroup as R. haematodes, R. chaetomallum, and R. catacosmum, but in those species the inflorescence is lax and few-flowered and the young stems and petioles are tomentose and without glands.

R. coelicum received an Award of Merit when shown by Col. The Lord Digby on April 19,1955 (raised from F. 21830).

From the Supplement (Vol. V)

Forrest’s 21830, mentioned under this species on page 637, has been identified as belonging to the closely related R. pocophorum.

R. × hemigymnum (Tagg & Forr.) Chamberlain R. chaetomallum var. hemigymnum Tagg & Forr. – A natural hybrid between R. pocophorum and R. electeum (Rev. 2, pp. 388–9).


R pocophorum Tagg

Closely allied to R. coelicum, differing in the glandular-bristly young shoots and petioles, and the glandular but not tomentose ovary. The leaves are also somewhat larger – up to 6 in. or slightly more long and 1{1/2} to 2{1/2} in. wide – and it attains about 10 ft in height, though usually less. According to the original description, there are fifteen to twenty flowers in the truss, but cultivated plants, even those raised from the wild seed, have far fewer. Most of the collections by Forrest and Rock are from the divide between the upper Irrawaddy and the Salween in S.E. Tibet, and the former introduced it from there in 1921. Tagg identified as R. pocophorum Kingdon Ward’s no. 8289 from the Delei valley, Assam, but neither his specimen nor the plants raised from the seed under this number agree well with this species.A plant at Nymans, raised from KW 8289, received an A.M. in 1971, on March 30, under the clonal name ‘Cecil Nice’.