Rhododendron monkoboense Argent

Folia Malaysiana 2003. 4(2): 113.

WFO ID: wfo-0000400259

IPNI ID: urn:lsid:ipni.org:names:70029627-1

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Description

Shrub or small tree to 2m. Twigs finely scaly and minutely but densely patently hairy but quickly glabrescent; internodes 1–2cm. Leaves arranged in pseudo­whorls of 2 or 3 together, or on young vigorous growth, spirally arranged. Blade 90–180 x 50–95mm, sub-ovate to broadly elliptic; apex broadly acute; margin flat and entire; base rounded to slightly cordate; upper leaf surface smooth to slightly rugose, glabrescent, lower surface laxly scaly. Scales small, with a small centre and lobed, silvery, thin flange. Mid-vein weakly raised above in the proximal 2⁄3, then becoming impressed, very strongly and broadly raised beneath throughout its length and finely striate when dry; lateral veins 7–16 per side, spreading almost at a right angle to the mid-vein, slender and hardly tapering until near the edge of the leaf, forking towards the margin, curving and anastomosing to form a weak but distinct, looping intramarginal vein and with a conspicuously raised reticulation viewed from above; beneath smooth with the lateral veins less conspicuous but still distinctly reticulate. Petiole 5–9 x 4–5mm, minutely patently hairy and scaly, almost rounded in section, somewhat flattened but not grooved above. Inflorescence an umbel of c.4 flowers. Pedicels 16–20 x 1.5mm, with a sparse to moderate covering of scales but no simple hairs. Flowers 75 x 72mm, yellow with a reddish flush; tube c.33 x 6 x 12mm, with a few sparse scales near the base outside otherwise glabrous, irregularly but densely short-hairy inside (but the hairs not in lines); lobes 45 x 35mm, slightly retuse at the apex. Stamens irregularly arranged; filaments c.34mm, densely hairy in the basal 1⁄3 becoming glabrous distally; anthers c.5 x 1.75mm. Disc apparently glabrous. Ovary 5–6 x c.2mm, sparsely scaly and covered with very short patent white hairs; style c.35 x 1mm, with a few scales in the basal 5mm, glabrous distally; stigma c.4mm in diameter. Fruit (immature) 30 x 5mm, fusiform, minutely hairy.

Distribution

Malaysia (Borneo), Sabah, known only from a few collections all from Mt Monkobo in the Beluran District.

Altitude

Habitat

Probably terrestrial in mossy forest on the summit area (1829m).

Nomenclatural History

Notes

References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:260