Rhododendron yunnanense Franch.

TSO logo

Sponsor

Kindly sponsored by Peter Norris, enabling the use of The Rhododendron Handbook 1998

Credits

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

Recommended citation
'Rhododendron yunnanense' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-yunnanense/). Accessed 2020-07-11.

Genus

Synonyms

  • R. chartophyllum Franch.
  • R. pleistanthum Balf. f.
  • R. aechmophyllum Balf. f. & Forr.
  • R. suberosum Balf. f. & Forr.
  • R. hormophorum Balf.f. & Forrest

Infraspecifics

Other species in genus

Glossary

corolla
The inner whorl of the perianth. Composed of free or united petals often showy.
included
(botanical) Contained within another part or organ.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
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.
ciliate
Fringed with long hairs.
glabrous
Lacking hairs smooth. glabrescent Becoming hairless.
microspecies
Species distinguished on the basis of minute differences of morphology. Generally used only for species that reproduce via apomixis (e.g. Sorbus).
style
Generally an elongated structure arising from the ovary bearing the stigma at its tip.
synonym
(syn.) (botanical) An alternative or former name for a taxon usually considered to be invalid (often given in brackets). Synonyms arise when a taxon has been described more than once (the prior name usually being the one accepted as correct) or if an article of the International Code of Botanical Nomenclature has been contravened requiring the publishing of a new name. Developments in taxonomic thought may be reflected in an increasing list of synonyms as generic or specific concepts change over time.

References

There are currently no active references in this article.

Credits

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

Recommended citation
'Rhododendron yunnanense' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-yunnanense/). Accessed 2020-07-11.

Shrub, (0.3-)1-6 m; young shoots scaly, sometimes also setose. Leaves evergreen to deciduous, 3-7 x 1.2-2 cm, narrowly elliptic to elliptic, apex acute, margin ciliate, at least when young, upper surface usually lacking scales, setose when young, the setae variably deciduous, midrib puberulent, lower surface with flat brown scales that are 3-5× their own diameter apart. Flowers 3-5, in a loose terminal inflorescence; calyx disc-like, usually ciliate; corolla white or pink to lavender, usually with dense red or yellow flecks, zygomorphic, widely funnel-shaped, 20-35 mm, outer surface usually lacking scales, glabrous; stamens 10; ovary densely scaly, occasionally puberulent at apex, style depressed, decimate, glabrous. Flowering May. Royal Horticultural Society (1997)

Distribution  Myanmar N China N & W Yunnan, W Sichuan, Guizhou

Habitat 2,100-3,950 m

RHS Hardiness Rating H5

Awards AM 1903 (F.W. Moore, Glasnevin, Dublin); flowers Pink, with brown spots. AM 1943 (Col Lord Digby, Minterne, Dorset) as R. hormophorum; flowers white, with a few buff spots. AGM 1993, to a clone 'Openwood'.

Conservation status Least concern (LC)

Taxonomic note This variable species is common in the wild. It is closely allied to R. pleistanthum (q.v.) and to R. davidsonianum (q.v.). Royal Horticultural Society (1997)

A semi-evergreen or nearly deciduous shrub, ultimately 8 to 12 ft high; stiffly and somewhat thinly branched; young wood slightly scaly. Leaves narrowly oval or obovate, 112 to 3 in. long, 12 to 34 in. wide, tapering at both ends, ciliate and sometimes sparsely bristly when young, bright green above, paler beneath, slightly scaly on both sides; stalk 14 in. or less long. Flowers produced in one or more clusters at the end of the previous year’s shoots during the latter half of May, each cluster consisting of four or five flowers. Corolla 112 to 2 in. across, widely funnel-shaped, white, pale blush, pale rose, or pale lavender, with a flare of brown, crimson, or sometimes greenish spots. Stamens ten, hairy at the base. Ovary scaly, style glabrous. Bot. Mag., t. 7614. (s. Triflorum ss. Yunnanense)

Native mainly of Yunnan and S.W. Szechwan, but extending into bordering parts of S.E. Tibet and upper Burma and also found in Kweichow. It was discovered by the French missionary Delavay and introduced by him to Paris in 1889. Messrs Veitch had plants in their Coombe Wood nursery by 1894, presumably raised from seeds obtained from Paris and one of these, received from Veitch, first flowered at Kew in 1897. Later, seeds were sent from China by Forrest, Kingdon Ward, and Rock, and the present garden stock mainly descends from these. In the wild R. yunnanense grows mainly in open places and seems, judging from Forrest’s field notes, to be partial to streamsides. Its altitudinal range is remarkably wide: Forrest’s collections from the Tali range were mostly from around 9,000 ft, a comparatively low altitude for that part of Yunnan, but around Atuntze, near the inner border of the rhododendron zone, he found it at 13,000 to 14,000 ft.

This very charming species is quite hardy, apart from a tendency to bark-split after late frost, when grown in an isolated position. Being by nature a thicket-forming shrub, and of rather gaunt habit on its own, it is best planted in a clump of several individuals or mixed with other scaly-leaved species of the same habit. It varies in the colour of its flowers, but the pure white or blush-tinted forms are really the most characteristic and most desirable. There is also great variation in the colour of the speckling, from light brown or green to crimson. It is easily raised from cuttings, but no clones have been named, which is surprising, considering what a variable species it is.

R.yunnanense received an Award of Merit on May 19, 1904, when shown from the Glasnevin Botanic Garden, Dublin; and an Award of Garden Merit in 1934.

From the Supplement (Vol. V)

The synonym R. pleistanthum should be deleted (page 809).

R. yunnanense is the central species of the Yunnanense aggregate – ‘a complex of six intergrading microspecies, which are often difficult to distinguish; the characteristics on which they are based are susceptible to great variation which is not always clearly correlated, either among the various characters themselves, or with geography’ (Cullen, Rev. 2, p. 65).

[R. hormophorum] – Included in R. yunnanense, which varies in the persistence of its leaves. But some plants grown as R. hormophorum are R. pleistanthum.

R. pleistanthum Balf.f. ex Hutch. – Included in R. yunnanense by Mr Davidian in his review of the Triflorum series (1963), this is resurrected in the Edinburgh revision, as a species similar to R. yunnanense but lacking bristles on the leaf margin and petioles and with a more northerly distribution.

Apart from this species and R. rigidum, the Yunnanense aggregate comprises R. davidsonianum, R. siderophyllum, given separate headings in the main work, and R. tatsienense, mentioned in this supplement under R. davidsonianum.


R hormophorum Balf. f. & Forr.

Synonyms
R. chartophyllum Franch. f. praecox Diels

This is really only a form of R. yunnanense with the leaves almost completely deciduous, in the sense that they are almost all shed by the time the new ones develop. Introduced by Forrest, and better known by the synonymous name. The wild plants are sometimes up to 9 ft high or, at the other extreme, have prostrate main stems creeping among or under stones and rocks, with erect branchlets only 1 to 1{1/2} ft high; cultivated plants are usually dwarfer and denser than in R. yunnanense. Award of Merit May 18, 1943, to a white-flowered form, leafless at flowering time, the foliage turning red in autumn, shown by Lord Digby, Minterne, Dorset.

R rigidum Franch.

Synonyms
R. caeruleum Lévl.
R. eriandrum Lévl, ex Hutch.
R. hesperium Balf. f. & Forr.
R. rarosquameum Balf. f.
R. sycnanthum Balf. f. & W. W. Sm

This species, better known as R. caeruleum, is allied to R. yunnanense, differing mainly in its quite glabrous, bluish-green leaves, glaucous green beneath. The flowers vary in colour from lilac or rosy pink to white, and are more or less spotted. It is fairly widely distributed in Yunnan and is said to be common in the north-eastern part of the province. The most admired form has white flowers, borne in May, and was introduced by Dr Rock under his no. 59207; it received an Award of Merit when exhibited by Lionel de Rothschild, Exbury, on May 16, 1939.

Feedback

A site produced by the International Dendrology Society.

For copyright and licence information, see the Licence page.

To contact the editors: info@treesandshrubsonline.org.