Rhododendron triflorum Hook. f.

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

Genus

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.
glabrous
Lacking hairs smooth. glabrescent Becoming hairless.
glaucous
Grey-blue often from superficial layer of wax (bloom).
lanceolate
Lance-shaped; broadest in middle tapering to point.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
ovate
Egg-shaped; broadest towards the stem.
style
Generally an elongated structure arising from the ovary bearing the stigma at its tip.
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.

Credits

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

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

Straggling shrub, (0.5–)1–5(–7) m; young shoots scaly, mature bark smooth and peeling, reddish brown. Leaves usually evergreen, 3.8–6.5 × 2–3.2 cm, ovate to lanceolate or elliptic, apex acute, upper surface lacking scales, glabrous, lower surface greyish brown, densely covered with small almost rimless brown scales. Flowers 2–4, in a loose terminal inflorescence; calyx small, scaly, not ciliate; corolla pale yellow, sometimes suffused with red, sometimes with greenish to red flecks, zygomorphic, funnel-shaped to widely funnel-shaped, 21–30 mm, outer surface densely scaly, pubescent at sinuses; stamens 10; ovary scaly, impressed below the declinate, glabrous or (rarely) puberulent at base, style. Flowering May-June. Royal Horticultural Society (1997).

Distribution  BhutanMyanmar N China S Tibet India Bengal, Manipur

Habitat 2,300–3,650 m

RHS Hardiness Rating H5

Conservation status Least concern (LC)

An evergreen shrub 6 to 10 ft high with glabrous, red, peeling bark; young shoots slender, glaucous, scaly. Leaves ovate-lanceolate, rounded at the base, sharply pointed, 2 to 3 in. long, 1 to 114 in. broad, bright green and glabrous above, glaucous and thickly furnished with scales beneath; stalk 14 to 13 in. long. Flowers fragrant, opening in May and June, usually in threes, at the end of the shoot when young growths are pushing. Calyx small, shallowly undulated; flower-stalks 12 to 78 in. long. Corolla pale yellow spotted with green, with a short funnel-shaped tube and five spreading oblong lobes giving the flower a diameter of 112 to 2 in., scaly outside. Stamens ten, 12 to 1 in. long, downy towards the base; ovary scaly; style longer than stamens, glabrous. (s. and ss. Triflorum)

Native of the eastern Himalaya; discovered by J. D. Hooker in the Sikkim Himalaya in 1849 and introduced by him. It is not a showy plant, although the flowers are interesting in their unusual colour. The red, semi-transparent, loose bark is also attractive with sunlight behind it. It is hardy.

From the Supplement (Vol. V)

The var. mahogani is not recognised in the Edinburgh revision, understandably so, as it is only a minor colour-form linked to the typical state by intermediates.

var. bauhiniiflorum (Hutch.) Cullen R. bauhiniiflorum Hutch. – The only distinguishing character of this variety is the widely expanded flower.


R bauhiniiflorum Watt ex Hutch

Very closely allied to R. triflorum but with more widely expanded flowers. Native of Assam in the Naga Hills and Manipur; discovered by Sir George Watt in 1881–2 but probably not introduced until Kingdon Ward sent seeds from Mt Japvo in 1928. It is a finer species than R. triflorum and almost as good as R. lutescens, besides being very much later-flowering. There is a fine clump in the Savill Garden, Windsor Great Park, which is about 10 ft high and was in flower in the fourth week of May in 1973.

var. bauhiniiflorum (Watt ex Hutch.) Cullen

Synonyms
R. bauhiniiflorum Watt ex Hutch.

Corolla very openly funnel-shaped to almost flat. Royal Horticultural Society (1997)

Distribution

  • India – Manipur

RHS Hardiness Rating: H5

The two varieties recognized here are distinguished only by the shape of the corolla. They apparently have different geographical distributions. Royal Horticultural Society (1997)


var. mahogani Hutch

This was found by Kingdon Ward in the Tibetan province of Kongbo, near Tsela Dzong on the Tsangpo, growing with the typical state. ‘Another rhododendron which grew here to perfection was R. triflorum and its dark variety, which I called the “Mahogany Triflorum” (K.W. 5687). In the valley it is a small compact scrubby plant with lemon-yellow flowers; but on these sheltered tree-clad slopes it formed a large bush 12 or 15 ft high with reddened flowers which were especially beautiful when the light shone through them…. The flowers vary from pale yellow – the typical R. triflorum colour – to salmon pink, mahogany, burnt sienna, and other tones. Moreover, the bushes were smothered in bloom and are as hardy as anything’ (Kingdon Ward, The Riddle of the Tsangpo Gorges, p. 44). This variety sounded promising, but proved a sad disappointment when it first flowered in gardens. ‘Was the dingy horror under the number KW 5687 shown in the Triflorum Class, was this the Mahogany Triflorum we have so anxiously awaited ?’(G. H. Johnstone in his Report on the Rhododendron Show for 1931).

var. triflorum

Corolla funnel-shaped to widely funnel-shaped.

Distribution Nepal, India (Sikkim, W Bengal, Arunachal Pradesh), Bhutan, N Burma, China (S Tibet).

Habitat 2,300–3,650m.

Taxonomic note (incl. R. triflorum Hook.f. var. maltogani Hutch.)