ABSTRACTS 



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BOTANY. — The Cactaceae, descriptions and illustrations oj plants oj the 

 Cactus Family. N. L. Brixton and J. N. Rose. Carnegie In- 

 stitution of Washington, Publication No. 248, Vol. I. Pp. 236, 

 pi. 36, figs. 302. June 21, 1919. 



This work is the result of a long study by the authors based on ex- 

 tensive field observations and greenhouse and herbarium studies. 

 The investigation has been chiefly financed by the Carnegie Institution 

 of Washington, in cooperation with the New York Botanical Garden 

 and the United States National Museum, while the United States De- 

 partment of Agricultiu-e has taken care of the living collections brought 

 together in Washington. 



The Cacti as here treated consist of a single order, Cactales, and of a 

 single family, the Cactaceae ; they are divided into three tribes, Pereskieae, 

 Opuntieae, and Cereeae. This volume contains the treatment of the 

 first tribes. The third tribe is to be treated in subsequent volumes. 



The tribe Pereskieae contains the single genus, Pereskia, in which 

 19 species are described. The second tribe, Opuntieae, contains 7 

 genera, Tacinga and Grusonia, each with a single species, Pterocactus 

 with 4, Maihuenia with 5, Nopalea with 8, Pereskiopsis with 10, and 

 Opuntia with 264, grouped into 3 subgenera and 46 series. 



The genera and species are described in detail and full synonymy is 

 given. One new genus, Tacinga and 42 new species are described. 

 All of the genera have been illustrated and of the 312 species, 267 are 

 represented by one or more illustrations. The illustrations consist of 

 36 plates of which 28 are in color, 3 are half-tones, and 5 are heliotypes. 

 The text-figures, 302 in number, consist of half-tones and zinc etchings. 



J. N. R. 

 408 



