Rhododendron mogeanum Argent

Folia Malaysiana 2003. 4(2): 111, pl.3.

WFO ID: wfo-0000400295

IPNI ID: urn:lsid:ipni.org:names:70029626-1

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Description

Shrub or tree to 4m. Twigs 3–4mm in diameter, rounded, whitish and densely brown-scaly, slowly becoming glabrescent; internodes 3–10cm. Leaves 3–6 together in tight pseudowhorls. Blade 50–86 x 30–45mm, broadly elliptic, elliptic or obovate; apex rounded and apiculate occasionally broadly pointed or slightly retuse; margin entire, narrowly cartilaginous, markedly revolute when dry; base cordate occasionally rounded or broadly tapering; laxly scaly and quickly glabrescent above, laxly and more persistently scaly below. Scales small (up to 0.2mm in diameter), with broad transparent margins and small to medium-sized dark centres which may become raised on circular swellings around the scale centre on older leaves. Mid-vein impressed above, prominently raised throughout its length below, where it is whitish; lateral veins 5–10 per side, slender, the basal 2–3 spreading almost at a right angle, the distal lateral veins spreading at c.45°, straight but branching and disappearing before the margin; reticu­lation obscure. Petiole 7–12 x 3–4mm, grooved above, deeply scaly and rugulose. Inflorescence an umbel with c.8 flowers. Pedicels 20–25 x c.0.7mm, erect, very densely brown scaly and with just a few, short, white, simple hairs. Calyx a low densely scaly disc. Corolla c.40 x 25mm, white or faintly pink; tube 25–28 x c.3 x c.4mm, densely scaly outside and shortly, patently, white-hairy inside; lobes c.13 x 10mm. Stamens with the anthers in the mouth of the corolla; filaments flattened and hairy in the proximal ¼, filiform and glabrous distally; anthers pale brown, c.3mm, sometimes apiculate at the base. Disc hairy on the upper margin. Ovary 4 x 1.75mm, scaly and shortly hairy with patent or slightly distally pointing hairs; style sparsely hairy and scaly in the basal ½, glabrous distally.

Distribution

Indonesia, C Kalimantan (Borneo), Mt Raya

Altitude

Habitat

Primary upper montane mossy forest.

Nomenclatural History

Notes

References

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