Kindly sponsored by
Peter Norris, enabling the use of The Rhododendron Handbook 1998
New article for Trees and Shrubs Online.
'Rhododendron mekongense' from the website Trees and Shrubs Online (treesandshrubsonline.
Shrub, to 2 m; young shoots scaly and variably setose. Leaves deciduous, obovate to obovate-elliptic, 2.5-4.5(6.5) x 1.4-2.1(-2.7) cm, apex rounded, margin ciliate, upper surface usually lacking setae at maturity, lower surface with a varying number of setae that are sometimes restricted to the base of the midrib and the margins, the scales of two kinds, the smaller tend to become greyish to purple or even black and are half the size of the larger. Flowers precocious, 2-4, in a terminal and sometimes also axillary inflorescence; calyx small; corolla yellow to greenish, 17-23 mm; stamens 10; ovary scaly, style sometimes puberulent at base. Flowering May. Royal Horticultural Society (1997)
Distribution Myanmar NE China S Tibet, W Yunnan Nepal
Habitat 2,900-4,400 m
RHS Hardiness Rating H5
Conservation status Least concern (LC)
R. chloranthum Balf.f. & Forrest
R. melinanthum Balf.f. & Kingdon-Ward
Corolla yellow or greenish-yellow, scales polymorphic in size and colour. Royal Horticultural Society (1997)
Var. mekongense has a surprisingly disjunct range, extending from SW China to Nepal. Royal Horticultural Society (1997)
R. rubrolineatum Balf.f. & Forrest
Corolla reddish yellow, scales varying in size but uniformly golden. Royal Horticultural Society (1997)
R. mekongense is closely allied to R. trichocladum (q.v.). Royal Horticultural Society (1997)