BALFOUR—NEW SPECIES OF RHODODENDRON. 283 
conspicue obovatis subtus erubescentibus, calycis lobis ellipticis 
haud setulosis, corolla majore praecipue distinguenda. 
Yunnan. Shweli-Salween Divide. Alt. 10,000-11,000 ft. 
Lat. 25° 30’ N. Shrub of 2-4 ft. Flowers fleshy bright sulphur- 
yellow. Open situations amongst dwarf scrub. G. Forrest. 
No. 11,910. April 1913 
This plant is the representative in the Shweli-Salween Divide 
of the Tali species Rh. sulfureum, Franch. It differs from Rh. 
_sulfureum in its much thicker and obovate leaves, in its larger 
flowers, and in the want of setae upon the calyx and elsewhere. 
This setulose character of Rh. sulfureum requires study. The 
setae are few in number in some plants—Delavay’s No. 2212 
and Forrest’s 41354 are not profusely setulose. The setae 
are in these species to be found only upon the calyx. But in 
Forrest’s No. 12,434 the setae are profuse beyond the calyx, 
spreading over the petioles and the stems also. Specimens in 
which the shoots are thus somewhat strigillose suggest specific 
difference, but there is amongst Mr. Forrest’s gatherings from 
the same locality and at the same date a gradation of forms 
from the extreme of abundance to the extreme of poverty in 
the matter of setae, and one must look upon the character as a 
varying one in the species. I find no setae on Rh. thetochroum. 
Mr. Forrest has another series of specimens from the Tali 
Range under numbers 4135B and 6777 which are esetulose. 
In this they resemble Rh. thetochroum as they do in the punc- 
tulate lepidoteness of their leaf under-surface. Their leaf form 
is, however, not obovate, and resembles more that of true Rh. 
sulfureum from which, in addition to the absence of setae, they 
are separated by this punctulate lepidoteness which is very 
different from the closer set indumentum of true Rh. sulfureum. 
Taking more minute characters Rh. theiochroum is readily 
diagnosed by its conoid long epidermal papillae from Rh. sul- 
fureum where they are low domes ; and in this character Forrest’s 
Nos. 4135B and 6777 are quite different from Rh. thetochroum, 
and approach, though they are not identical with, Rh. sulfureum. 
I have not named Forrest’s 41358 and 6777 as a distinct species, 
although I think it is one. What I have said about it may 
suffice to direct attention to it as a microform of Rh. sulfureum 
to be looked for. 
I add here some notes made during the sifting of the 
material which has given the species described in the preceding 
pages. They are fragmentary, but I publish them because it 
is unlikely that I shall deal with these Rhododendrons again, 
