Description

Slender shrub to 60cm. Twigs 1–3mm in diameter, rounded, green but distinctly brown-scaly; internodes 2–7cm. Leaves 3–7 together in tight pseudowhorls, together with conspicuous, subulate, cataphylls. Blade 25–80 x 6–30mm, narrowly elliptic or very narrowly ovate; apex long-acuminate and often somewhat curved, acute; margin slightly recurved; base tapering to rounded or weakly cordate, rugose, especially when dry, moderately densely scaly on both sides initially, becoming glabrescent above, more persistently scaly beneath. Scales brown, sessile, highly variable, the largest deeply, stellately lobed, or sub-dendroid; centre small and not impressed. Mid-vein distinctly impressed above and very thick and prominent beneath; lateral veins 7–13 per side, widely spreading, slightly to strongly raised above and impressed beneath (especially when dry) so as to make the surface rugose, reticulation obscure. Petiole 2–4 x c.2mm, distinctly grooved above, densely brown-scaly. Flower buds to 20 x 7mm, narrowly ovoid, acute, pale green although prominently brown-scaly. Outer bracts subulate with the tips slightly spreading, inner ones larger, ovate-acuminate, acute, the points mostly appressed, stellate-scaly outside, and with scales along the margins, often persistently clasping the flower after it has opened. Flowers solitary or in twos, horizontal or half-hanging. Pedicels 3–5 x c.2mm, densely stellately scaly. Calyx c.2.5mm in diameter, oblique, shortly 5-lobed, scaly outside. Corolla 35–45 x 55–65mm, deep, bright yellow, saucer-shaped; tube 12–15 x 8–9 x 16–20mm, but contracted in the middle to c.7mm, white with scattered brown scales outside and deeply sulcate in the proximal ½, distally, yellow, smooth and glabrous, except for small clusters of scales at the junctions with the lobes, glabrous inside; lobes 20–30 x 17–25mm, spreading almost horizontally and overlapping ½–2⁄3, broadly obovate with rounded or emarginate apices. Stamens c.18mm; filaments slender, bent through a right angle, glabrous at the base, hairy above the angle and then glabrous distally; anthers linear-oblong, 4–5 x 1–1.5mm. Disc prominent, hairy at the upper margin. Ovary c.8 x 4mm, sub-cylindrical, with long, white, sub-patent hairs which cover scales, abruptly contracted distally; style 10–15mm, glabrous, yellow, at first deflexed downwards or to one side; stigma club-shaped, becoming deeply 5-lobed. Fruit 35–43 x 5–6mm, fusiform-cylindric, densely hairy with a persistent style up to 13mm; valves reflexing and twisting after opening. Seeds 7.5–9.5mm, without tails 0.6–0.7mm, the longest tail 4–5mm.

Distribution

Indonesia, Kalimantan. Brunei. Malaysia (Borneo), Sabah and Sarawak. Widespread throughout Borneo.

Altitude

Habitat

Mostly epiphytic in dense humid forest, along rivers particularly near waterfalls, also recorded from ‘heath-forest’.

Nomenclatural History

Notes

References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:204