Rhododendron wardii W. W. Sm.

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Credits

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

Recommended citation
'Rhododendron wardii' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-wardii/). Accessed 2020-08-07.

Genus

Synonyms

  • Rhododendron croceum Balf. f. & W. W. Sm.
  • Rhododendron gloeoblastum Balf. f. & Forr.
  • Rhododendron oresterum Balf f. & Forr.
  • Rhododendron prasinocalyx Balf. f. & Forr.
  • Rhododendron astrocalyx Balf. f. & Forr.

Infraspecifics

Other species 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.
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.
apex
(pl. apices) Tip. apical At the apex.
cordate
Heart-shaped (i.e. with two equal lobes at the base).
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).
obtuse
Blunt.
orbicular
Circular.
ovate
Egg-shaped; broadest towards the stem.
petiole
Leaf stalk.
style
Generally an elongated structure arising from the ovary bearing the stigma at its tip.
truncate
Appearing as if cut off.
abaxial
(especially of surface of a leaf) Lower; facing away from the axis. (Cf. adaxial.)

References

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Credits

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

Recommended citation
'Rhododendron wardii' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-wardii/). Accessed 2020-08-07.

Shrub or small tree, 0.6-8 m. Leaves 6-11 x 2.3-6 cm, often glaucous when young, base cordate, glabrous. Flowers 5-15, in a lax to dense truss, white to sulphur yellow, buds often strongly tinged pink, with or without a basal blotch, open-campanulate (saucer-shaped), nectar pouches lacking, 25-40 mm; ovary and style stalked-glandular. Flowering May-June. Royal Horticultural Society (1997)

Distribution  China SE Tibet, NW Yunnan, SW Sichuan

Habitat 3,000-4,300 m

RHS Hardiness Rating H5

Conservation status Least concern (LC)

Taxonomic note R. wardii hybridizes in the wild with R. selense (see under R. x erythrocalyx) and with R. vernicosum. Where its range overlaps with R. campylocarpum (in S Tibet) the two species apparently intergrade, probably due to local hybridization. These two are sometimes confused but R. wardii can always be distinguished by its glandular style. Royal Horticultural Society (1997)

An evergreen shrub up to 15 or 20 ft high in the wild; young shoots sometimes glandular, otherwise glabrous. Leaves thinly leathery, glabrous, varying in shape from nearly orbicular to ovate, oblong-elliptic or oblong, rounded to obtuse at the apex, rounded, truncate or somewhat cordate at the base, 114 to 434 in. long, 1 to 212 in. wide, dark or medium green above, paler, sometimes rather glaucous, beneath; petiole 38 to 114 in. long. Flowers in a loose terminal truss of up to fourteen, opening in May; pedicels up to almost 2 in. long, usually glandular. Calyx five-lobed up to 12 in. long, usually glandular. Corolla five-lobed, cup-shaped to saucer-shaped, up to 212 in. across (exceptionally to 3 in. across), pure yellow, sometimes with a crimson blotch inside at the base. Stamens ten. Ovary conoid, glandular; style glandular from base to tip. Bot. Mag., n.s., t. 587. (s. Thomsonii ss. Souliei)

R. wardii is a species of wide range, from S.W. Szechwan westward through N.W. Yunnan to S.E. Tibet, in the provinces of Tsarong, Kongbo, and Takpo, but has not been reported from Burma. It occurs at 10,000 to 14,000 ft, in open thickets or occasionally as undergrowth in coniferous forest or deciduous woodland. It was discovered by one of the French missionaries, but was first validly described from specimens collected in 1913 by Kingdon Ward and by Forrest, both of whom sent seeds in that year. The former found it on the Doker La and around Atuntze, in the north-western corner of Yunnan; the latter 120 miles farther east, in the mountains of the north-east Yangtse bend. There have been many further sendings since then, the most recent being by Ludlow and Sherriff shortly before and after the second world war.

From R. souliei and R. puralbum, its nearest allies, R. wardii differs only in the colour of its flowers. From R. campylocarpum to which it is also nearly related, it can be distinguished by the style being glandular throughout and by the shallower corolla, but in some plants from Ludlow and Sherriff seeds the corolla is rather deeper than is typical for this species. It also resembles R. campylocarpum in the range of flower-colour, from pale creamy yellow, lemon, or sulphur to deep primrose, and in the frequent presence of a crimson or maroon blotch at the base of the corolla.

R. wardii is perfectly hardy near London and needs only light shade. Some of the strains introduced by Ludlow, Sherriff, and Taylor are valuable for the small garden, or one where late frosts are frequent, as they flower late in May and are of bushy compact habit, besides being beautiful in flower. All the seed collected came from the Tibetan Himalaya near Molo (c. 94°E.), some of it from as high as 13,000 ft.

Several forms of R. wardii have received Awards of Merit:

April 27, 1926, as R. croceum, flowers lemon-yellow, and as R. astrocalyx, flowers bright yellow with a small crimson flash (both shown by A. M. Williams, Werrington Park, Cornwall);

May 19, 1931, as R. wardii KW 4170, flowers bright yellow, green-flushed, raised from seeds collected by Kingdon Ward in the Muli area of S.W. Szechwan in 1921 (Lionel de Rothschild, Exbury);

May 5,1959, as R. wardii “Ellestee”, probably from seeds collected by Ludlow, Sherriff, and Taylor, flowers clear yellow with a deep crimson blotch (Collingwood Ingram, Benenden, Kent);

May 20, 1963, as R. wardii ‘Meadow Pond’, from Ludlow, Sherriff, and Elliot 15764, flowers primrose-yellow with a deep crimson blotch (Crown Estate Commissioners, Windsor Great Park).

From the Supplement (Vol. V)

var. puralbum (Balf.f. & W.W. Sm.) Chamberlain – This was mentioned under R. souliei on page 774 and in this supplement.

[R. litiense] – Included in R. wardii (Rev. 2, p. 266). R. wardii thus now has six synonyms instead of five and becomes only slightly more variable than it was before. The sinking of R. litiense is no more to be lamented than the loss of R. croceum and R. astrocalyx, both submerged in R. wardii many years ago.


R litiense Balf. f. & Forr

Closely allied to R. wardii and, like it, having the style glandular to the tip; differing in the always oblong leaves, markedly glaucous beneath, and in the rather smaller, less saucer-shaped corollas. For a discussion of the taxonomic position of this species see R.Y.B. 1951-2, p. 157. It is a native of N.W. Yunnan, discovered and introduced by Forrest. Award of Merit, May 19, 1931, when shown by Lionel de Rothschild, Exbury, and a First Class Certificate in 1953 on the same date.

var. puralbum (Balf.f. & W.W.Sm.) D.F.Chamb.

Synonyms
R. puralbum Balf.f. & W.W.Sm.

Flowers pure white. Royal Horticultural Society (1997)

This may be no more than an albino form of the much more common var. wardii. Royal Horticultural Society (1997)


var. wardii

Synonyms
R. astrocalyx Balf.f. & Forrest
R. litiense Balf.f. & Forrest

Flowers clear yellow. Royal Horticultural Society (1997)

Awards
AM 1926 (A.M. Williams, Launceston) as R. croceum; flowers bright yellow, touched with crimson internally. AM 1926 (A.M. Williams, Launceston) as R. astrocalyx; flowers flat, clear lemon yellow. AM 1931 (L. de Rothschild, Exbury) from Kingdon-Ward 4170; flowers bright yellow, flushed green. AM 1931 (L. de Rothschild, Exbury) as R. litiense; flowers yellow. AM 1959 (Capt. c. Ingram, Benenden, Kent) to a clone 'Ellestee', from L., S. & T. 5679; flowers clear Lemon Yellow, with a crimson blotch. AM 1963 (Crown Estate Commissioners, Windsor) to a clone 'Meadow Pond', from L., S. & T. 15764; flowers Primrose Yellow, with a crimson blotch. FCC 1953 (Col Lord Digby, Minterne, Dorset).

Forms with relatively narrow leaves that are more glaucous than the type, from a restricted zone around the Li-ti-ping in W Yunnan, have been referred to R. litiense. This taxon is not maintained as it merges with the type form that has broader leaves. There are no significant differences in the flower characters. Royal Horticultural Society (1997)

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