The Boothii series is a fairly homogeneous group, as noted in "The Species of Rhododendron" (p.155). Most of the species are small shrubs with yellow flowers, with the exception of the now well-known R. leucaspis (white), and R. deleiense and R. tephropeplum, which have magenta-rose or somewhat crimson flowers. The series as a whole is most nearly allied to that of Glaucum, but a tendency towards the Maddenii group is shown by R. chrysolepis, and by the epiphytic habit of R. Boothii and R. cerinum, and occasionally of R. megeratum. R. tephropeplum was discovered by Farrer (No. 1567) in 1920 in the Chawchi and Maguchi Passes in north-east Burma, at an altitude of 3200 m. Since then it has been gathered several times by Forrest, Kingdon Ward and Rock, a list of these collections being given by Tagg in Rhod. Soc. Notes, III. 82 (1926). It gained an Award of Merit at the Rhodo- dendron Show in 1929, and it is now too well known and sufficiently appreciated as a fine low-growing garden plant to need eulogy here. The leaves of the wild specimens are very striking when examined under a microscope, the scales on the lower surface being quite black above the glaucous layer of wax-covered papillae. Miss E. M. Wakefield has kindly examined these.

Syn. R. spodopeplum Balf. f. & Farrer, 1.c. 299 (1922); Millais, l.c. 242 (1924); Cox, Farrer's Last Journey, 238 (1926).