ro HutTCHINSON—THE MADDENI SERIES OF RHODODENDRON. 
unwettable to water from the outside and restraining the exit 
of water from within the leaf. In species of the laxly lepidote 
series where the exposed leaf surface is largest—Rh. Vettchianum, 
Hook., Rh. formosum, Wall., Rh. Dalhousiae, Hk. f. for example 
—the epidermal papillae are long rod-like outgrowths with 
parallel sides standing out at right angles from the epidermis 
and more or less closely packed. In no one of the densely 
lepidote series are those papillae long rod-like and close-set but 
more or less conoid or in the form of low domes having wider 
spaces between than in the case of rods with parallel sides. 
Sometimes where a scale fringe arches over the leaf surface the 
papillae are longer than elsewhere. There is clearly a correlation 
between the form of papillae with their wax and the covering 
of peltate scales. That the southern types Rh. Veitchianum, 
Hook., and Rh. formosum, Wall., are conspicuously laxly lepidote 
with grey white bloom may be noteworthy in relation to their 
habitat.”’ 
Certain species need special mention. These are R. Dal- 
housiae, Hk. f., R. formosum, Wall., and R. inaequale, 
Hutchinson. 
R. Dalhousiae, Hook. f. 
In the examination of the dried material of Rhododendron 
Dathousiae 1 have detected a very fine species of Rhododendron 
which appears to have been overlooked by Sir Joseph Hooker. 
R. Dalhoustae was described by Hooker in his account of the 
Sikkim Rhododendrons, p. 2, t. i and ii (1849). The first plate 
of that work is a picture of the plant as it grows epiphytically 
on trees in Sikkim (see extracts from Hooker’s Journal below). 
The second plate was drawn by Fitch from Hooker’s original 
sketch, and evidently also from the dried specimens. Emphasis 
is laid on the latter fact, because it seems partly responsible for 
the confusion of two species. Amongst Sir Joseph’s exsiccatae 
is one sheet marked “ Rhod. xiv. J. D. Hooker, Sikkim Hima- 
laya 1848, 6-8000 ft.’’ It is a fine leafy flowering branchlet, 
and in the corner is a solitary fruit which certainly does not 
belong to it. This specimen differs from typical R. Dalhousiae 
(as represented by Hooker’s original sketch and by the remainder 
of his dried specimens) in having only scaly pedicels (not hairy 
as well), broad membranous striate calyx lobes with a dense 
fringe of soft hairs on the margin (in true Dalhousiae they are 
narrower and not fringed), a corolla with a tube only 5 cm. long 
(much smaller than in typical Dalhousiae), which is ee 
scaly outside the base; the leaves also- differ. from typical 
Dathousiae in that they are elliptic and more or less rownded 
; 
