Description

Shrub or tree to 15m. Twigs 2–4mm in diameter, rounded, sparsely scaly, quickly glabrescent; internodes 2–10cm. Leaves 3–7 together in tight pseudowhorls. Blade 40–140 x 25–50mm, elliptic, ovate-elliptic, or obovate-elliptic; apex shortly acuminate, acute or obtuse to rounded; margin entire, flat or weakly and narrowly revolute; base tapering to broadly tapering, laxly scaly and quickly glabrescent above; laxly to sub-densely scaly below. Scales rounded to weakly sub-stellately lobed, flat, with a broad margin and small slightly impressed centre. Mid-vein narrowly impressed above, weakly to strongly raised below; lateral veins 4–10 per side, spreading at 45–90°, curving before the margin, minutely impressed above, and smooth to weakly raised below, reticulation obscure to faintly visible on both sides. Petiole 5–12mm, grooved above, scaly. Flower buds to 15 x 12mm, spherical, often with an outer collarette of narrow subulate spreading or reflexed bracts, these often disappearing near maturity so that the bud is then smooth. Outer bracts ovate, inner ones sub-circular, obovate to spathulate with rounded or apiculate apices, all laxly scaly and minutely hairy outside and fringed with scales. Bracteoles to 15 x 1mm, linear to filiform, sub-spathulate distally, very laxly hairy or glabrous. Inflorescence of 5–15 flowers in a complete umbel. Pedicels 25–50 x c.1mm, slender, sparsely scaly, normally without hairs, but sometimes laxly covered with very fine, short hairs. Calyx 2–3mm in diameter, oblique, rounded, the lobes indistinct, margin often scaly. Corolla 10–25 x 20–30mm, shortly tubular or tubular-campanulate, light yellow to orange or yellow at the tube and/or centre, reddish orange at the lobes, variable in size, mostly scentless; tube 10–12 x 3–5 x 4–6mm, straight, 5-angular, lobed at the base, laxly scaly outside, densely hairy inside; lobes 12–20 x 8–14mm, broadly obovate-spathulate, laxly scaly outside, glabrous inside. Stamens strongly exserted to 15mm, spreading around the mouth of the flower, unequal; filaments linear and densely covered with spreading hairs in the proximal ½, glabrous and narrower distally; anthers 2.5–3.2 x c.1mm. Disc with thick lobes, mostly glabrous, rarely shortly hairy in the upper ½. Ovary c.4 x 1.8mm, elongate-conical, densely covered with sub-appressed hairs, which completely cover scales, tapering distally; style 10–15mm, densely to laxly hairy and scaly in the proximal ½, glabrous distally; stigma rounded to distinctly lobed. Fruit 35–45 x 3–5mm, fusiform, often slightly curved, strongly 5-ribbed, hairy and scaly. Seeds c.4mm including the long tail at both ends.

Distribution

Indonesia and Papua New Guinea. Widespread over the whole mainland of New Guinea.

Altitude

Habitat

Common and locally abundant, sometimes colouring hillsides with its flowers, mostly terrestrial, occasionally epiphytic, both in primary mossy forest, secondary shrubberies and often persisting in anthropogenic grassland in dry sunny situations.

Nomenclatural History

R. hansemanni Warb., Bot. Jahr. 1892. 16: 26. R. vonroemeri Koord., Nova Guinea 1912. 8: 879, t.155. R. lauterbachianum Foerster, Fedde Rep. 1914. 13: 224. R. calceolarioides Wernham, Trans. Linn. Soc. London, II, Bot. 1916. 9. R. gorumense Schltr., Bot. Jahr. 1917. 55: 142.

Notes

References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:305