Rhododendron megeratum

Description with 24 photos. Photo: Finn Bertelsen. Erect, but low, evergreen shrub. hardiness unknown. Young shoots light greenish, later brownish, scaly and setose. Leaves shiny, dark green, convex-concave due to recurved apical margins, non-aromatic, elliptic to obovate, to 43 x 21 mm. Petiole scaly and setose, to 15 mm. Apex rounded, with mucro. Leaf base rounded to rounded cuneate. Leaf upper side with scattered bristles near base and along leaf margin (young leaves), without scales. Leaf lower side light glaucous, with some bristles near base, micro-papillose, with scattered, unequal, brown scales, 90 – 180 micrs., sunk in pits, 1 – 3 x their diameter apart. On juvenile leaves the scales are transparent and vesicular. Inflorescence terminal with 2 flowers. Pedicel setose, to 19 mm. Calyx with 5 lobes, narrow elliptical, elepidote, with a few marginal hairs, 10 mm. Corolla with 5 lobes, openly campanulate, pale yellow, externally with scattered vesicular scales, internally glabrous, c. 40 mm wide, c. 20 mm deep (long). Ovary ovoid, tapering into the style, densely covered by vesicular scales, with 5 loculi, 3 mm. Stamens 10, 50 – 100 % puberulent, with red-brown anthers, 3.3 mm. Style bent 90 degrees, glabrous, 8 mm, with green turbinate stigma, 1.2 mm. Capsule and seeds unknown. Locality of origin: Dulong, Gongshan County, NW Yunnan, China at 3100 m. The upright growth differs from the general view of the species being low and cushion like. However, Davidian, H.H. (1982, The Rhod. Spec., V 1) mentions a growth height up to 5-6 ft. The scale distance on the abaxial side of leaves is 0.5 – 1 x d in Flora of China (no source given), 1 – 1.5 d in Davidian and c. 2 x d in Feng Guomei (1988, Rhod. China V 1). There seems to be some uncertainty regarding these distances. Earlier I have mistakenly referred the specimen to Rh. chrysodoron due to the scale distance and growth form. With the first occurrence of flowers – 2 yellow ones in the inflorescence – it is however obvious to change the determination to Rh. megeratum.