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Rhododendron chaetomallum Balf. f. & Forr.

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Credits

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

Recommended citation
'Rhododendron chaetomallum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-chaetomallum/). Accessed 2024-09-14.

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.
included
(botanical) Contained within another part or organ.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
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).
included
(botanical) Contained within another part or organ.
lax
Loose or open.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
style
Generally an elongated structure arising from the ovary bearing the stigma at its tip.
subspecies
(subsp.) Taxonomic rank for a group of organisms showing the principal characters of a species but with significant definable morphological differentiation. A subspecies occurs in populations that can occupy a distinct geographical range or habitat.
variety
(var.) Taxonomic rank (varietas) grouping variants of a species with relatively minor differentiation in a few characters but occurring as recognisable populations. Often loosely used for rare minor variants more usefully ranked as forms.

References

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Credits

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

Recommended citation
'Rhododendron chaetomallum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-chaetomallum/). Accessed 2024-09-14.

An evergreen shrub up to 4 or 5 ft high; young shoots thickly clothed with twisted, bristly hairs. Leaves obovate, rounded at the end, tapered at the base, dark green and glabrous above except when quite young, velvety with a coat of tawny down beneath, 2 to 4 in. long, 1 to 13⁄4 in wide; stalk 1⁄5 in. long, stout, hairy like the shoot. Flowers in clusters of six to ten opening in March and April, on bristly stalks. Calyx red, up to 3⁄8 in. long, with five lobes unequal in shape and size. Corolla bell-shaped, 13⁄4 in. long and 21⁄2 in. wide, deep crimson, five-lobed. Stamens ten, up to 1 in. long, glabrous; anthers chocolate brown. Ovary densely woolly; style glabrous. Bot. Mag., n.s., t. 25 (s. Neriiflorum ss. Haematodes)

R. chaetomallum was discovered by Forrest in 1917–18 on the Mekong-Salween divide, N.W. Yunnan, growing in open thickets and on boulder-strewn slopes at 11,000 to 13,000 ft and was introduced by him at the same time under F. 14987, collected under the sacred mountain Ka-kar-po. From the Mekong it ranges westward across upper Burma and a variety has been discovered in the eastern Himalaya.

It is a variable species, distinguished from other members of the Haematodes subseries by the more or less bristly but not glandular young shoots and petioles, the lax, few-flowered truss, and the tomentose but not glandular ovary. Although a handsome species, it flowers too early for most gardens. The Award of Merit was given on April 7, 1959, to a form with Turkey Red flowers, raised at Exbury from Forrest 25601, collected on the Nmai (E. Irrawaddy)-Salween divide. The wild plants were said to have almost black-crimson flowers.

From the Supplement (Vol. V)

This is included in R. haematodes as a subspecies. The varieties mentioned are disposed of as follows:

[var. chamaephytum] – Possibly a natural hybrid between R. forrestii (or R. chamaethomsonii) and R. haematodes.

[var. glaucescens] – Included in R. haematodes subsp. chaetomallum.

[var. hemigymnum] – A natural hybrid between R. pocophorum and R. eclecteum – R. × hemigymnum (Tagg & Forr.) Chamberlain.

[var. xanthanthum] – Probably part of hybrid swarms involving R. catacosmum, R. citriniflorum and R. temenium.

var. chamaephytum Cowan

Near var. hemigymnum but prostrate and almost glabrous. Described from Ludlow, Sherriff, and Taylor 3786, collected in the eastern Himalaya above Molo, near the border between Tibet and Assam.

var. glaucescens Tagg & Forr

Leaves rather glaucous above.

var. hemigymnum Tagg & Forr

Indumentum of leaf-undersurface thinner than normal, tending to wear off as the season advances. Forrest’s 25605 is referred to this variety, but a plant raised from the corresponding seed-number at Tower Court, which received an Award of Merit in 1957, has the leaves densely brown-tomentose beneath.

var. xanthanthum Tagg & Forr

Flowers creamy yellow flushed or striped with rose or rosy crimson; or striped and margined bright rose-pink on a yellowish base.

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