Rhododendron orbiculare Decne.

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Credits

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

Recommended citation
'Rhododendron orbiculare' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-orbiculare/). Accessed 2024-03-19.

Genus

Synonyms

  • Rhododendron rotundifolium Franch.

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.
apex
(pl. apices) Tip. apical At the apex.
corolla
The inner whorl of the perianth. Composed of free or united petals often showy.
glabrous
Lacking hairs smooth. glabrescent Becoming hairless.
glandular
Bearing glands.
glaucous
Grey-blue often from superficial layer of wax (bloom).
midrib
midveinCentral and principal vein in a leaf.
orbicular
Circular.
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 orbiculare' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-orbiculare/). Accessed 2024-03-19.

Shrub or tree, 1.5–15 m. Leaves 7–12.5 × 5.6–7.7 cm, orbicular to ovate-orbicular, base cordate, lower surface glabrous. Flowers 10–17 in a truss; calyx c.0.5 mm; corolla 7-lobed, deep rose-pink, campanulate to open-campanulate, nectar pouches lacking, 35–40 mm; stamens 14; ovary stalked-glandular, style glabrous. Flowering April-May. Royal Horticultural Society (1997)

Distribution  China Sichuan, Guangxi

Habitat 2,500–4,000 m

RHS Hardiness Rating H5

Awards AM 1922 (Hon. H.D. McLaren, Bodnant); flowers rose pink.

Conservation status Vulnerable (VU)

Taxonomic note Only subsp. orbiculare, with orbicular leaves, is known in cultivation. Royal Horticultural Society (1997)

An evergreen shrub up to 6 or 10 ft high; young shoots stout, purplish, glandular. Leaves almost orbicular, but usually somewhat longer than broad, 2 to 4 in. long, deeply auricled at the base, rounded at the apex, with a minute tip formed by a slight prolongation and thickening of the midrib; quite glabrous, dark green above, glaucous beneath; stalk 112 to 2 in. long, very stout. Flowers borne in April or May, up to ten or so in a terminal truss 6 in. across; flower-stalks glabrous, up to 214 in. long. Calyx minute, glabrous. Corolla widely bell-shaped, 2 to 212 in. across, seven-lobed, pale magenta-pink. Stamens about fourteen, shorter than the corolla. Ovary glandular, style glabrous. Bot. Mag., t. 8775. (s. Fortunei ss. Orbiculare)

Native of W. Szechwan, China; discovered by Père David around 1870; introduced to Britain by Wilson in 1904. It is a very distinct rhododendron, making a dense bush of rounded habit if not crowded. But the flowers are usually of a cold shade of bluish pink which is far from attractive. It received an Award of Merit in 1922.

From the Supplement (Vol. V)

subsp. cardiobasis (Sleumer) Chamberlain R. cardiobasis Sleumer – This is mentioned under R. orbiculare on page 733, as a related species.


R cardiobasis Sleum

Leaves similar in shape to those of R. orbiculare, but cordate (not auricled) at the base, and somewhat larger. It differs markedly from R. orbiculare in having the pedicels and rachis glabrous, and the style (as in ss. Fortunei) glandular to the tip. It was described from a specimen collected in Kwangsi province, S. China, a region remote from the homeland of R. orbiculare.