Description

Shrub to 3m. Twigs rounded, green, 2–3mm in diameter, sparsely to sub-densely covered with flat, pale brown scales; internodes 4–10cm. Leaves 4–6 together in tight pseudowhorls, sessile or sub-sessile. Blade 80–175 x 24–50mm, elliptic; apex gradually or abruptly acuminate, acute or broadly acute; margin entire, flat, often red; base broadly tapering to rounded or sub-truncate, occasionally slightly cordate, often with conspicuous ‘ear-like’ folds at the base; sparsely scaly and quickly glabrescent above, persistently and more densely scaly beneath. Scales small, irregularly shallowly lobed with dark centres, slightly impressed, remaining brownish punctate after the scales have gone. Mid-vein wide, as thick as the petiole at the base, raised above for the proximal ½–¾, impressed in a broad shallow groove beneath; lateral veins 10–13 per side, spreading at an acute to a wide angle, straight below, curved distally, indistinctly anastomosing, very slightly raised above, smooth and often obscure beneath, reticulation mostly obscure. Petiole 2–4 x 2–4mm, without a groove, densely scaly. Flower buds (see p.327) ovoid, to 35 x 18mm, pale green or sometimes flushed with pink, outer bracts standing out away from the bud, the larger ones with deeply channelled sub-subulate points. Bracts almost totally glabrous outside, with a minute fringe of fragile marginal scales, glabrous inside, ovate to ovate-long-acuminate. Bracteoles to 15 x 2mm, sub-filiform, glabrous. Inflorescence an open to full umbel of 5–10 semi-erect to horizontal, pale yellow, scentless flowers. Pedicels 25–30 x 1–1.5mm, laxly-scaly, without hairs. Calyx c.4mm in diameter, oblique, rim-like, obscurely lobed. Corolla 25–50 x 41–50mm, broadly funnel-shaped; tube 20–22 x 8–9 x 17–18mm, glabrous outside and laxly hairy inside, base deeply sulcate; lobes 20–30 x 15–22mm, reflexed to the perpendicular or beyond, overlapping 1⁄3–½, obovate. Stamens exserted to c.15mm, irregularly arranged around or mostly on the lower side of the mouth, sub-equal; filaments linear and densely sub-patently hairy in the proximal ¼, glabrous distally; anthers c.4 x 1.3mm, broadly oblong, cream coloured. Disc prominent, deeply lobed, glabrous. Ovary 5–7 x 2.5–3mm, cylindrical, narrowed towards the base, sub-glabrous, with just a few scattered scales and sometimes with a few hairs near the base, abruptly contracted distally; style 12–28mm, glabrous, lying on the lower side of the tube, curving upwards distally as the stigma becomes receptive; stigma 3–4mm in diameter, rounded. Fruit 35–40 x 8–10mm, sub-cylindrical.

Distribution

Indonesia, Sumatra, Tapanuli, East Coast, West Coast.

Altitude

Habitat

Terrestrial, or rarely epiphytic, in open primary or secondary forest, roadsides and crater sides, locally common.

Nomenclatural History

Notes

References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:251