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, 
Tiflis, 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. Sundermann (Lindau), 
H. Correvon (Geneva), Haage & 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 (California). 
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. Henrioues (Portugal). 
Mrs. Henshaw (British Columbia). 
Rev. Pere E. E. Mai re (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 have been obtained, and 
many requests for material, which in happier times might have had 
interesting results, were rendered abortive. 
VIIL Notes on the Text. 
A word as to the arrangement of the material under each species. 
Following on the reference to original publication, 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 familiar species references to standard works are omitted. 
