Description

Shrub to 1m. Twigs green, rounded, rough with hairs and scales; internodes 1–3cm. Leaves in dense pseudowhorls of 8–12. Blade 12–27 x 12–18mm, broadly elliptic, oblong or obovate; apex broadly pointed, or rounded occasionally slightly retuse; margin entire, slightly recurved, often red; base rounded to tapering; covered with simple white hairs and sub-densely scaly. Scales irregularly lobed with a broad marginal flange and small impressed centre. Mid-vein slightly impressed above and broadly but shallowly raised beneath for most of its length; lateral veins obscure or 3–5 per side, slightly raised below and spreading at c.45°. Petiole 1.5–3 x 2.2–2.6mm, green, hairy and scaly, broadly but shallowly grooved on the upper side. Flower buds (see p.327) 18 x 10mm, ovoid, purplish red, surrounded by a collar of green, narrowly triangular, to subulate cataphylls; outer bracts narrowly ovate with subulate protruding tips; inner bracts broadly ovate with mucronate appressed apices, densely silvery white hairy distally on the outer sides, less densely so on the inner side. Inflorescence of 7–8 white or pale purplish-pink semi-erect to horizontal flowers in an open umbel, without scent. Pedicels c.10 x 1.25mm, densely white-hairy and with some brown scales. Calyx a low, densely white-hairy ring. Corolla occurring in two size classes: large, c.26 x 45mm with the tube c.17 x 15 x 7mm and lobes 22 x 24mm; and small, c.25 x 31mm x 29mm, tube 12 x 5 x 10mm and lobes c.16 x 15mm, with scattered brown scales outside and some simple hairs inside on the tube; lobes semi-erect to spreading, overlapping from 2⁄3 to most of their length and with some brown scales outside. Stamens clustered below the mouth of the flower; filaments 9mm, broadening and hairy in the proximal 1⁄3; anthers 3 x 1mm, brown, incurved to completely obscure the stigma when young, later straightening. Ovary 3 x 3mm, densely white hairy with semi-erect hairs; style 3mm, rough, hairy at the base otherwise glabrous; stigma 1.5–2.5mm in diameter. Fruit 16 x 8mm, the valves stiffly spreading, only slightly curving. Seeds 2mm, without tails 1.1mm, the longest tail 0.5mm.

Distribution

Malaysia (Borneo), Sabah.

Altitude

Habitat

It is only known growing terrestrially around the summit of Mt Tambuyukon. In open shrubby vegetation amongst ultramafic rocks.

Nomenclatural History

Notes

References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:198