Rhododendron phaeochrysum Balf.f. & W.W.Sm.

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

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

Genus

Other taxa in genus

Glossary

Credits

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

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

Shrub, 1.2–4.5 m. Leaves 4–14.5 × 1–6.5 cm, elliptic to ovate-oblong, apex acute to apiculate, lower surface covered with a one-layered compacted or felted, sometimes agglutinated, brown indumentum composed of radiate to sub-ramiform hairs; petioles floccose. Flowers 8–15, in a dense truss; calyx c.1 mm; corolla white flushed pink, with crimson flecks, funnel-campanulate, nectar pouches lacking; ovary glabrous or with a few papillate hairs, style glabrous. Flowering April-May. Royal Horticultural Society (1997)

Distribution  China S Tibet, NW Yunnan, SW & C Sichuan

Habitat 3,350–4,200 m

RHS Hardiness Rating H5

Conservation status Least concern (LC)


R alutaceum Balf.f. & Forr

Near to R. phaeochrysum, the main key-difference being the relatively narrower leaves, 2 to 634 in. long and 1 to 158 in. wide (length:breadth ratio 2.2–6:1 against 1.7–3(4):1 in R. phaeochrysum) (Rev. 2, p. 337). There are two varieties apart from the typical one, not clearly demarcated from each other:

R traillianum Forr. & W.W. Sm

This species is allied to the preceding two, though clearly distinct in having a ‘powdery’ indumentum composed of a single layer of short- or long-rayed rust-coloured hairs. Bot. Mag., t.8900. A native of west Yunnan and south-west Szechwan, described from a specimen collected by Forrest in the Lichiang range.

var. agglutinatum (Balf.f. & Forr.) Chamberlain

Synonyms
R. agglutinatum Balf.f. & Forr.
R. dumulosum Balf.f. & Forr

Leaves 4–9 cm, indumentum agglutinated, sometimes splitting; corolla 20–35 mm. Royal Horticultural Society (1997)

Like the preceding, but the indumentum agglutinated, often splitting.The species as a whole is of wide distribution in the less rainy parts of the Sino-Himalayan region, from western Szechwan through north-west Yunnan to south Tibet. It may have been introduced by Wilson, as R. taliense, when collecting for Veitch, but most cultivated plants are from later sendings by Forrest and by Rock (although some in Sweden are from seed collected by Harry Smith in the area of Kangding (Tatsien-lu), grown as R. cuprescens).


var. alutaceum

Synonyms
R. glohigerum Balf.f. & Forr.
R. roxieanum var. globigerum (Balf.f. & Forr.) Chamberlain

Indumentum woolly, pale brown.

var. dictyotum (Tagg) Chamberlain

Synonyms
R. dictyotum Tagg

This replaces var. traillianum in north-west Yunnan. The indumentum resembles that of var. traillianum, though the component hairs are slightly different (Rev. 2, p. 354).All these species and their varieties are worthy of cultivation, if they can be obtained, with attractive, though not showy, dense trusses of white or pink-tinted, spotted flowers, borne mostly in April. They are of interest as representing a type of rhododendron that is very common in the wild.

var. iodes (Balf.f. & Forr.) Chamberlain

Synonyms
R. iodes Balf.f. & Forr

Indumentum with a brown, felted upper layer.

var. levistratum (Balf.f. & Forr.) Chamberlain

Synonyms
R. levistratum Balf.f. & Forrest

Leaves 4–9 cm, indumentum felted, continuous; corolla 20–35 mm. Royal Horticultural Society (1997)

Awards
AM 1977 (R.N.S. Clarke, Borde Hill, Sussex) to a clone 'Greenmantle', Rock 11325 (USDA 59229); flowers white, with a small red blotch.

This species shows considerable variation in the leaf indumentum. It apparently merges with R. przewalskii in C Sichuan (q.v.) and hybridizes with R. aganniphum and perhaps other species in Subsect. Taliensia. Most cultivated plants named R. dryophyllum should be referred to var. levistratum; the type of R. dryophyllum is however referrable to var. phaeochrysum. Royal Horticultural Society (1997)

Syns: all those given under the heading R. dryophyllum on page 651. This variety is what was described as typical R. dryophyllum on that page. It differs from var. phaeochrysum only in its shorter leaves and smaller flowers.


var. phaeochrysum

Synonyms
R. dryophyllum Balf.f. & Forr. (type only)
R. cuprescens Nitzelius

Leaves 8–14.5 cm, indumentum felted, not splitting; corolla 32–50 mm. Royal Horticultural Society (1997)

The leading characters of this, the typical variety, are: leaves not bullate above, 3 to 512 in. long, elliptic to ovate-oblong, with a brown, densely felted, sometimes agglutinated tomentum beneath. Inflorescence rachis about 12 in. long. Calyx very small. Corolla funnel-campanulate, white flushed pink, with crimson markings in the throat, up to 2 in. long. Ovary glabrous or almost so. See further on page 652.


var. russotinctum (Balf.f. & Forr.) Chamberlain

Synonyms
R. russotinctum Balf.f. & Forr.
R. triplonaevium and R. tritifolium Balf.f. & Forr

Indumentum rust-coloured, not woolly, the upper layer discontinuous.