BALFOUR—NEW SPECIES OF RHODODENDRON. 127 
Yunnan. Mountains of the Chungtien plateau. Alt. 
II,000-12,000 ft. Lat. 27° 55’ N. In thickets. Shrub of 
20 ft. In fruit. G. Forrest. No. 10,914. Aug. 1913; Lat. 
27° 35’ N. In open thickets. Shrub of 20-30 ft. Flowers 
pale lavender-rose or white flushed rose with deep red markings. 
G. Forrest. No. 12,435. April 1914. 
Yunnan. G. Forrest. No. 11,421. Sept. 1913. 
Yunnan. Lichiang Range. Alt. 11,000-12,000 ft. Lat. 
27° 40' N. G. Forrest. No. 11,738. Oct. 1913. 
Yunnan. Mountains N.W. of Chien Chuan. Alt. 10,000- 
II,000 ft. Lat. 26° 30’ N. Flowers? Open pine forests. 
Shrub of ro ft. G. Forrest. No. 13,035. July 1914. © 
This is one of the rhododendrons which attracts attention 
by the snow-white under-surface of the rather long mature 
leaves. Many of the leaves show a dingy spotting and may 
take on a brown colour. This is due to the attack of an 
ascomycetous fungus which spreads all through the indumentum. 
The hairs of the upper stratum of indumentum are often very 
long, and the delicate branches ascend as loose not interwoven 
threads above the lower stratum, which forms a typical roof 
over the epidermis. The short stalks of the hairs appear as so 
many pillars supporting the vesicular branches spreading out 
horizontally from the top, and the branches of adjacent hairs 
becoming agglutinated form the smooth scintillating indumental 
surface. In the chamber covered by these matted branches the 
stomata project as domes above the epidermal surface. 
In this indumental character of the mature leaves RA. 
niphargum resembles Rh. uvarifolium, Diels (1912),* as it does in 
such other features as the many-flowered compact globose truss 
of flowers at the end of thick branches encircled by a rosette of 
more or less deflexing leaves, the small glabrous calyx, 5-lobed 
campanulate corolla, 10 unequal stamens with puberulous 
filaments, thin dark-coloured ovary puberulous with very short 
vesicular pointed hairs, the style glabrous slightly longer than 
stamens, shorter than corolla, and ending in a stigma hardly 
wider than the style itself which does not expand clavately 
beneath it. Rh. niphargum has the foliage-buds and all young 
parts enclosed in a snow-white indumentum—and I take it 
that in nature these show up after the fashion of those of the 
East Himalayan Rh. niveum, Hook. f, and the Szechwan Rh. 
floribundum, Franch.—the striking beauty of which matches 
if it does not surpass that of their flowers. Whether this is the 
; ilsoni i 6, is this 
* Rh. Monbeigi, Rehd. et Wilson, Plantae Wilsonianae, i (191 3), 536, 
species. See of it came to Edinburgh from Pére Monbeig in 1907, and I 
have compared them with those from the same source in Kew Herbarium under 
the numbers cited by Rehder and Wilson. : 
