BOTANY. 381 



BOTANY. 



Britton, N. L., and J. N. Rose, U. S. National Museum, Washington, D. C. 

 Studies of the Cactacece. (For previous reports see Year Books Nos. 

 11-16.) 



The work on the cactus project has proceeded very satisfactorily 

 during the year. Now that the results of this investigation are being 

 published one becomes impressed with the great amount of detail 

 required to bring this material together. 



The first volume was issued June 21, 1919, and the second Septem- 

 ber 9, 1920. The third volume is now in proof and will soon appear. 

 The fourth volume is well advanced. 



It has required more time, patience, and money to prepare for pub- 

 lication the results of the investigation than was anticipated, for it 

 has been found necessary to build up large living and herbarium col- 

 lections before constructive work could be done. There have been 

 assembled in New York and Washington the largest collections of 

 cacti that have ever been made and, inasmuch as they will form the 

 basis of study in all future monographic work on this family, great 

 pains have been taken to make them as complete as possible. 



The field work done by the Institution has been chiefly in the cactus 

 deserts of South America and the W^est Indies. It has been impossible 

 to do any field work in Mexico since 1912, owing to the political dis- 

 turbances in that country, although it is the greatest cactus region in 

 the world. 



Field work should still be done along the boundary between Texas 

 and Mexico, where a number of species are known only from the work 

 of the early Boundary Survey. There is also a large cactus area 

 included in southern Brazil and Uruguay which is known only from 

 isolated accounts and meager collections. 



Fortunately, the field work of the Institution has been richly sup- 

 plemented by the most generous assistance of botanists and collectors 

 throughout North and South America. Each week brings in some 

 rare or undescribed plant. A case in point will be of interest here. 

 Soon after the final proof of Volume II had been sent to the printer, 

 Dr. W. L. Abbott sent a cactus from Haiti which was identified as a 

 very rare species, first collected by Charles Plumier about 1696, but 

 never properly classified, and which proved to be the type of an un- 

 described genus. It was named Neoahhottia and an account of it was 

 published in the Smithsonian Contributions to Knowledge. During 

 the past year (September 1, 1920, to September 1, 1921) about 500 

 numbers of living cacti and more than 1,000 specimens have been sent 

 in by some 60 voluntary collectors and have been grown in the cactus 

 houses of the U. S. Department of Agriculture and of the New York 

 Botanical Garden. A number of the duplicates have been distributed 



