20 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



(Great Warley) ; and a number of nurseries, including those of Messrs. 

 Backhouse (York), Cunningham, Fraser & Co. (Edinburgh), the 

 TuLLY Nursery (Kildare), Lissadell Nursery (SHgo), &c. 

 Plants were also received from : 



Christiania, Botaniske Have, 

 Tifiis, Botanic Garden, 

 Washington, Smithsonian Institution, 

 St. Louis, Missouri Botanic Garden, 



and from many private gardens and nurseries, including those of 

 Messrs. Kegel & Kesselring (Petrograd), F. StJNDERMANN (Lindau), 

 H. Correvon (Geneva), Ha age & Schmidt (Erfurt), and at home those 

 of Messrs. Bees, Ltd., T. S. Ware, J, Wood, Clarence Elliott, 



Bo WELL. 



My best thanks are due to a number of foreign botanists who sent 

 collected plants or seeds, and thus helped in many cases to introduce 

 additional species into cultivation, some of which have proved to be 

 new to science : 



L. R. Abrams (CaUfornia). 



D. M. Andrews (Colorado). 



The Director, Botanical Survey of India (Darjeeling). 



Miss Eastwood (California). 



Reginald Farrer (Kansu). 



Prof. H. M. Hall (California). 



Prof. J. A. Henriques (Portugal). 



Mrs. Henshaw (British Columbia). 



Rev. P^re E. E. Maire (Yunnan). 



Dr. G. V. Perez (Teneriffe). 



Mrs. Stoker (British Columbia). 



E. R. Warren (Colorado). 



The baneful influence of the European war hindered work after 

 the first year of the period of my investigation, and subsequently 

 stopped practically all intercourse with foreign countries so far as 

 the receipt of material was concerned. I was unable to carry out a 

 trip which had been planned to include gardens at Frankfurt, Darm- 

 stadt, Vienna, Lindau, Geneva, and Paris, at some of which, I have 

 no doubt, additional species of Sedum would hcve been obtained, and 

 many requests for material, which in happier times might have had 

 interesting results, were rendered abortive. 



VIII. Notes on the Text. 



A word as to the arrangement of the material under each species. 

 Following on the reference to original pubhcation, a limited number 

 of further references are added to writings where the species has 

 been especially fully dealt with. More references are given to obscure 

 species or those new to cultivation than to well-known ones — in 

 the case of famihar species references to standard works are omitted. 



