90 TRANSACTIONS OF THE [Sess. lxxs 



inflorescence it is further removed from the Kansu plant 

 of Przewalski (type of D. tanguticum) than is the Yunnan 

 plant cultivated in this country under D. tanguticuvi. It 

 is in cultivation, and its behaviour there is all in favour of 

 its specific distinctness ; in the form of the leaves and in 

 the structure of the flower its tanguticum affinity is 

 undoubted, yet no observer at first sight would imagine 

 them to be even closely related. This dissimilarity led us 

 then to doubt the correctness of the view which associated 

 the Yunnan " D. tanguticum" with the typical Kansu 

 plant. The Yunnan plant has a distinct habit which is 

 definite even in the first year's growth ; its flowers are 

 twice the size of those of the Kansu plant — worthy of note, 

 although we would not attach much weight to that char- 

 acter if it stood alone. The plant ought to have a dis- 

 tinguishing name, and as on its first appearance in the 

 Royal Botanic Garden as a cultivated plant it bore for a 

 while the name D. Forrestii, we propose to restore that 

 appellation. A diagnosis is given below. 



Another plant of the series is found on the Tali 

 Range, more closely allied, in our opinion, than any of 

 the others to the Kansu D. tanguticiim. It is described 

 below as D. taliense. Its area of distribution is in the 

 Mekong basin, separated by a long and very high mountain 

 range from the habitats of the other Yunnan species. 

 Of these D. Isahellae and D. iwajyinqtium appear to be 

 confined to the Chungtien plateau ; D. Forrestii, at its 

 optimum in the Lichiang Range, has outliers on the same 

 plafeau. 



In our view then there are five species of this section 

 with pinnatifid leaves known from China. Two have 

 very large flowers, D. Isahellae, D. Forrestii ; D. tanguticum, 

 flowers of moderate size ; D. propinquum, D, taliense, 

 flowers decidedly smaller than those of the other species. 

 In the Royal Botanic Garden during 1915 three of these 

 were in flower — J). Forrestii, D. Isahellae, D. propinquum ; 

 the differences between them are manifest both in the 

 early and in the late stages of development. 



JJracocep/ialviii. Forr^'stii, W. AV. Sm. 8p. nov. 



Species ^'alde jifliiiiM />. /(i/ugtUico, Maxim, sed liabitu. 



