Rhododendron psammogenes Sleumer

Reinwardtia 1960. 5: 150.

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Description

Erect shrub to 1m. Twigs rounded, at first, laxly covered with minute pale scales, later glabrescent; internodes 3–10cm. Leaves in well-marked pseudowhorls. Blade 25–55 x 14–28mm, elliptic; apex broadly tapering, then often almost rounded and very shortly apiculate; margin entire, narrowly revolute; base broadly tapering or rounded, initially scaly on both sides, gradually glabrescent above, sub-densely scaly beneath. Scales pale reddish-brown, minute, marginal zone variously lobed; centre impressed. Mid-vein impressed above, thick and prominent beneath proximally, less prominent distally; lateral veins 5–6 per side, irregular, straight proximally, obscurely anastomosing, slightly impressed above, slightly or not raised beneath. Petiole 2–4mm, thick, flat. Bracts to 10 x 5mm, ovate to ovate-elliptic or sub-spathulate, membranous, scaly outside, or quickly glabrescent, margin fringed with scales or very shortly irregularly toothed. Bracteoles to 10mm, linear, laxly scaly. Inflorescence a 7–9-flowered open umbel. Pedicels 25–30 x c.1.5mm, densely covered with thick, lobed scales. Calyx c.3mm in diameter, oblique, irregularly 5-toothed to 1mm, but sometimes up to 3mm, elongate-triangular and acute. Corolla 30–33mm, funnel-shaped, sub-oblique, white or pale yellow, thin; tube 18–20 x 3–4 x 4–5mm, cylindrical, densely covered with thick, sub-circular, lobed scales outside, with white spreading hairs in the lower ½ of the corolla tube inside; lobes 10–12 x 7–8mm, spreading, obovate-spathulate, shallowly retuse. Stamens exserted to c.5mm, unequal; filaments linear and densely patently hairy proximally, more slender and glabrous distally; anthers c.2.5mm, oblong. Disc glabrous below, shortly yellowish hairy on the upper margin. Ovary c.5 x 2mm, sub-cylindrical, densely covered with scales and white, forwardly directed hairs, gradually tapering distally; style slender, laxly patently hairy and scaly in the lower 1⁄3–½, glabrous distally, as long as or slightly longer than the stamens; stigma thick, rounded.

Distribution

Indonesia, New Guinea (W), Balim R. Valley, at 2100m, terrestrial amongst bracken in unfertile sandy soil.

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References

Argent, G. (2006) Rhododendrons of subgenus Vireya. RHS:London. Page:222