Description

Shrub. Twigs 2–3mm in diameter, rounded, upper ones densely scaly and laxly hairy; internodes 3–6cm. Leaves 3–4 together in pseudowhorls. Blade 80–120 x 30–55mm, broadly elliptic to elliptic-oblong, with somewhat unequal sides; apex obtuse to rounded, often minutely retuse; margin sub-revolute; base broadly tapering to nearly rounded; glabrescent above except for some hairs at the base, laxly scaly beneath. Scales small, deeply sub-stellate-dentate, flat; centre red-brown, small, slightly impressed. Mid-vein distinctly impressed above, thick and prominent beneath proximally, less so distally; lateral veins 6–8 per side, well spaced, straight below, curved-anastomosing before the margin, slightly impressed above, a little prominent beneath, reticulation indistinct. Petiole 6–13 x 2–4mm, glabrous or with some hairs, rough, grooved above. Bracts to 13 x 10mm, ovate, glabrous, irregularly shortly sub-serrate. Bracteoles c.10mm, linear, laxly hairy. Inflorescence 7–10-flowered. Pedicels 20–30mm, densely covered with patent greyish hairs, very laxly scaly. Calyx c.2mm in diameter, disc-shaped, inconspicuous. Corolla trumpet-shaped, pale red-violet when fresh; tube c.35 x 3–4 x 3–4mm, cylindrical, base inflated and 5-lobed, hardly or not widened towards the mouth, densely covered all over with soft greyish hairs outside, also inside in the proximal ½; lobes 10–12 x 5–7mm, obovate-rounded, spreading, densely hairy outside except near the margin, glabrous inside. Stamens unequal, as long as the corolla; filaments linear, flattened, densely whitish hairy to the proximal 1⁄3, glabrous distally; anthers 2.5 x 0.8mm, oblong, base obtuse. Disc with a few scattered hairs. Ovary 4–6 x 1.5–2mm, cylindrical, 5-ribbed, densely covered with sub-patent hairs, tapering distally; style slender, c.2/3 of the length of the corolla, laxly covered with spreading hairs in the proximal 1⁄3; stigma narrowly obconical.

Distribution

Indonesia, Kalimantan, summit of Mt Kemul.

Altitude

Habitat

In ridge forest, on humus-rich peaty soil

Nomenclatural History

R. trichanthum Sleumer, Reinwardtia 1960. 5: 127, non Rehder, J. Arn. Arb. 1945. 26: 480.

Notes

References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:168