BOOK REVIEWS 

 Rydberg's Flora of the Prairies and Plains 1 



In the center of our country lies a most interesting type of 

 vegetation, in which grasses are the predominant feature. It oc- 

 cupies a great triangle of land, with its base stretching more 

 than a thousand miles north and south along the eastern foot- 

 hills of the Rocky Mountains and its apex extending east to 

 Indiana. This is the Prairie Province of Pound and Clements. 



The flora of this region has been studied more than a cen- 

 tury, but the results of the study have not always been accessi- 

 ble to the student or local botanist. The seventh edition of 

 Gray's Manual (1908) covered an area west through Minnesota 

 and to the ninety-sixth meridian in Kansas and Nebraska. Coul- 

 ter and Nelson (1909) included in their area all of Colorado and 

 Wyoming and a part of South Dakota. Britton and Brown 

 (1913) set the one hundred and second meridian for their west- 

 ern boundary, while Rydberg (1922) took the same line for his 

 eastern boundary. The whole territory has been covered there- 

 fore, in its northern part at least, but always in manuals de- 

 signed primarily for other types of flora in adjacent regions. 



Now we have a much-needed book which centers on the 

 prairie flora and covers the six states North Dakota, South 

 Dakota, Nebraska, Kansas, Minnesota, and Iowa. It also ex- 

 tends into the southern parts of Manitoba and Saskatchewan, 

 serves well for the eastern parts of Montana, Wyoming, and 

 Colorado, for northern Missouri, and for the prairie plants of 

 Wisconsin, Illinois, and Indiana. 



Like all manuals covering political divisions of a country, it 

 is not strictly limited to the prairie flora. The northeastern third 

 of Minnesota is largely occupied by coniferous forests of the 

 eastern type, the Black Hills by similar forests of the western 

 type, and the eastern deciduous forests invade the territory in 

 long strips following the river valleys almost to its western 

 boundary. The extreme southeastern corner of Kansas is occu- 

 pied by a distinctively southern flora, so that four types of for- 

 est flora are included in the book. Then the Sonoran element of 



1 Rydberg, P. A. Flora of the prairies and plains of central North America. 

 Pages vi, 969. 600 figures. The New York Botanical Garden, Bronx Park, New- 

 York. 1932. $5.50. 



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