R. caeruleum Lévl.
R. eriandrum Lévl, ex Hutch.
R. hesperium Balf. f. & Forr.
R. rarosquameum Balf. f.
R. sycnanthum Balf. f. & W. W. Sm
, differing mainly in its quite glabrous, bluish-green leaves, glaucous green beneath. The flowers vary in colour from lilac or rosy pink to white, and are more or less spotted. It is fairly widely distributed in Yunnan and is said to be common in the north-eastern part of the province. The most admired form has white flowers, borne in May, and was introduced by Dr Rock under his no. 59207; it received an Award of Merit when exhibited by Lionel de Rothschild, Exbury, on May 16, 1939.