139 



Kearney and Peebles have studied the Arizona plants, Deam has 

 lived with those of Indiana. This statement is in no sense a reflection 

 upon the Arizona authors and their comprehensive survey of their 

 state's vegetation ; it is merely a summation of the differences in 

 "flavor" between the two volumes. 



Certain of the families and genera of included plants, as in 

 Beam's Flora, have been treated by recognized experts in these 

 groups; in this respect, as well as others, one may justifiably say 

 that the authors approached their problem in the "modern" sys- 

 tematic manner. Well written — that is as well written as any 

 manual, consisting primarily of keys, species-descriptions and 

 records of distribution, can be written — and rather adequately il- 

 lustrated with definitely good photographs, the Flora also contains 

 an interesting discussion of the mantle of vegetation which, though 

 torn and frayed by climate and topography, covers Arizona. To one 

 who is addicted to maps as an aid to the interpretation of vegeta- 

 tional studies, a detailed map of the state, showing the major floris- 

 tic areas and accompanying F. Shreve's discussion of vegetation 

 types, is a desideratum which might well have been included. An 

 outline map giving county limits, larger rivers and principal lo- 

 calities is a multiple guidepost to the "visitor" who dips into the 

 book. 



Among the more interesting facts presented, at least to one 

 whose inclination is also toward things phytogeographic, is the pres- 

 ence in Arizona of two ferns, Asplenium exigniiin and Cetararch 

 daUwnsiae. The isolated Arizona stations listed, together with a few 

 localities for the former in northern Mexico, constitute the known 

 western hemisphere records of these two species whose primary 

 distribution is the Himalaya Mts., elsewhere in eastern Asia, and 

 Abyssinia. 



As an indication of the scope and complexity of the flora of Ari- 

 . zona, approximately 3,200 species, representing 128 families, are 

 treated, and the estimate is made that when the state is complete- 

 ly explored the total may well be more than 3,500 species. The 

 diversity of vegetation is due to several factors; among them the 

 altitudinal range and climatic variation, and the resultant com- 

 plexity of ecological habitats, within the state, as well as the num- 

 ber of primary vegetation-centers from which the components of 

 the Arizona flora have come. 



