102 
leaving for America, so that in many instances Mr. Hemsley 
alone is responsible for the final determinations here published. 
The following sketch of the Rhododendron vegetation of China 
was written by Mr. Wilson before his last journey, and he has had 
no opportunity of revising it ; but the points dealt with are probably 
not susceptible of important modification. The original plan of the 
authors was limited to the publication of the new species in 
Mr. Wilson’s collections, but the opportunity now offered has been 
taken to give determinations of all the specimens received at Kew 
since the appearance in 1889 of the enumeration of the species then 
known, published in the Journal of the Linnean Society of London, 
vol. xxvi. In doing this the numbers of the various collectors are 
cited, so that this addition may be of use to other institutions 
possessing sets of these dried plants. 
A few modifications in the spelling of placenames have been 
admitted, the following being the most important :—Tatienlu for 
Tatsienlu ; Szechuan for Szechuen ; Omi for Omei, and Yangtsze 
for Yangtze. 
Il. Tue Distrisution oF RHODODENDRONS IN CHINA. 
One of the outstanding features of recent botanical exploration 
in China is the wealth of Rhododendrons discovered. Up to the 
present time, and exclusive of the new species hereinafter described, 
no fewer than 134 species are known to occur in China proper: 
pit Rhododendron is one of the largest genera recorded trom 
‘hina. 
The Index Kewensis enumerates to date (December, 1906) some 
305 species of Rhododendron distributed as follows :—China proper, 
134 species ; Malaya, 62 species; British India, 46 species ; Japan 
and Corea, 28 species; North America, 19 species; Orient, 
six species; Europe, four species ; Siberia, three species ; Arctic 
regions, two species ; and Australia, one species. From Africa and 
from Central and South America the genus is absent. The above 
figures show conclusively that the headquarters of the genus is 
China. Now, a cursory knowledge of the distribution of the 
Chinese Rhododendrons is sufficient to prove that the centre of 
the greatest concentration of species is the wild and rugged region 
of the China-Tibet borderland—which region is a continuation of 
the Himalayas. The optimum is somewhere between Mupine, 
long. 102° .30', lat. 31° about, and Talli, long. 100°, lat. 25° 50° 
about. North of Mupine, Rhododendrons rapidly decrease in 
numbers, and in _the extreme north-west of Szechuan and in 
Kansu, comparatively few species occur. The same obtains in 
the country south of Tali. 
_ In China, the genus Rhododendron extends from sea-level to the 
limits of ligneous vegetation. There is no heather (Calluna or 
Erica) in China, and its place on the alpine moorlands is taken by 
dwarf, small-leaved Rhododendrons such as R. fastigiatum, R. 
nigro-punctatum, R, intricatum, and R, blepharocalys. : 
The low-level species, such as R. indicum and R. sinense, are 
abundant on scrub-clad hills, but whilst the former extends from 
