Description

Shrub to 3m. Twigs smooth, rounded, sparsely covered with pale brown, lobed scales; internodes 2–20cm. Leaves in tight pseudowhorls of 4–5 large and a similar number of very small leaves and with well-spaced cataphylls on the internodes when young. Blade 60–110 x 20–55mm, elliptic; apex rounded or slightly retuse; margin entire, broadly revolute, the whole leaf being convex; base broadly tapering. Mid-vein impressed in a channel above and strongly raised below throughout its length; lateral veins 5–8 per side, diverging at c.45°, slightly raised; above sparsely covered with small, lobed, pale scales with brown centres, quickly glabrescent; below sparsely covered with more persistent scales impressed in shallow depressions. Scales small, brown, lobed. Petiole 10–25 x 3–5mm, weakly grooved above, especially distally, sparsely scaly. Flower buds to 15 x 12mm, ellipsoid to ovate, the tips of the scales spreading outwards and dark, shiny, red, remainder pale green flushed with pink, the outermost bracts often becoming brown, with appressed hairs and brown scales outside. Outermost bracts mucronate, main bracts broadly elliptic with rounded apices, scaly and appressed hairy in the distal ½ outside, glabrous inside. Bracteoles c.12 x 1mm, filiform but channelled adaxially, sometimes sub-spathulate, with a few scales especially along the margins and occasionally with sparse simple white hairs. Inflorescence 5–10-flowered, in an open umbel, the flowers semi-erect to horizontal. Pedicels 13–18 x 1–1.5mm, dark red with scattered scales and patent white hairs. Calyx disc-shaped, shallowly 5-lobed, patently hairy. Corolla 30–36 x 20–30mm, dark purplish-red, without scent; tube 20–25 x 5–6 x 8–9mm, cylindrical, curved, sulcate near the base, shortly patently white hairy outside and with a few small silvery scales; inside with white hairs only in the proximal 2–3mm otherwise glabrous; lobes 10–12 x 9–10mm, overlapping ¼–½, spreading, hairy outside and with some small silvery scales, rounded or weakly emarginate. Stamens clustered on the upper side of the mouth, exserted to c.4mm; filaments 22mm, hairy at the base for c.3mm, glabrous distally; anthers 1.5–2mm, pale brown. Ovary 3–4 x 2–3mm, shortly cylindrical, densely covered with semi-appressed white hairs and white scales, abruptly contracted distally; style 16–18mm, glabrous; stigma disc-shaped. Fruit 11–15 x 5–7mm, broadly ellipsoid, the valves spreading to 45° or weakly curving back; placentae adhering to the central column or weakly spreading from the base. Seeds c.2.5mm, without tails 0.8–0.9mm, the longest tail to 1mm.

Distribution

Malaysia (Borneo), Sarawak, Mt Mulu, Mt Tamacu, (Mulu Nat. Park), Mt Murud. Sabah, Crocker Range, Mt Alab, (not yet recorded from Mt Kinabalu); Mt Lumarku and Long Pa Sia area.

Altitude

Habitat

In mossy montane forest on ridges where it is predominantly terrestrial but it may also grow epiphytically.

Nomenclatural History

Notes

References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:265