220 TRANSACTIONS OF THE [Sess. lxxxi 



RIl. gymnanthum, which Forrest describes as a " shrub of 

 3-6 ft.," the leaves are long (as much as 19 cm.) narrowly 

 (in the longest leaves some 3" 5 cm. broad) lanceolate and 

 willow-like, with a slight curvature in the direction of sickle 

 shape, and the upper surface is glaucous green conspicuously 

 glossy. In Rh. tanastylum, which Ward speaks of as a 

 " medium-sized scraggy bush or more generally thin tree 

 of 20 ft.," the leaves do not show a length beyond 13"5 cm. 

 and their width is 43 cm. ; they are therefore much shorter, 

 their width is greater in relation to their length, and their 

 general form runs from lanceolate and broadly lanceolate 

 to lanceolate oval sometimes oblanceolate oval, and there 

 is no curvature ; their upper surface is dark olive-green or 

 brownish-olive and the under surface is darker. The leaf 

 margin in Rh. gyinnanthuin is nearly flat and its undula- 

 tions are not conspicuously developed, but in Rh. tanastylum 

 the margin is prominently recurved and the undulations 

 give an appearance of crenulation. In the flower region 

 the inflorescence-rhachis becomes glabrous and smooth in 

 Rh. gyranantJium but may retain a few floccose hairs ; in 

 Rh.. tanastylum it develops a curious furfuraceous surface, 

 giving the impression of very minute puberulousness. The 

 pedicels in Rh. gynmanthAini are more slender ; its corolla 

 is funnel-shaped campanulate not tubular-campanulate and 

 is somewhat shorter ; the staminal filaments are puberulous. 

 Our specimens of both plants are scanty and have neither 

 foliage nor flower-buds nor yet fruits, and the flower 

 material of Rlt. tanastylum is particulai-ly small in amount. 

 What we have suffices to distinguish the species, although 

 it is inadequate for tlieir complete description. 



Since this paper was read and printed, additional species 

 of the Irroratum section have become known. '^I'hey are : — 



Bh. eriog'i)nu'm,lia,U. E. Upper Jkirina. Fen - Shin- Ling Camp. 



-' f. et Ward. 8000-9000 ft. (Ward.) 



Rh. facetum, Ball', f. Mid. W. Yunnan. Clii Slian, E. of Tali Lake, 



et W. W. Sill. 9000 ft. (Forrest.) 



Specimens of Hh. Kr/iulrickii, Nutt., collected by R. E. 

 Cooper in Bhutan, whicli I have examined, tell me that its 

 affinity is with the Irroratum series and not with Rh. 

 arbo7-eum, Sin. 



