BOOKS AND CURRENT LITERATURE 171 



several factors involved in this complex relationship. Further work 

 along shnilar lines should lead ultimately to much broader generaliza- 

 tions regarding the salt requirements of plants and the specific effects 

 of their constituent elements upon plant growth than now obtain. — 



W. E. TOTTINGHAM. 



Flora of the Northwest Coast. — The rapidly growing hst of 

 western floras has been augmented by the recent appearance of Piper 

 and Beattie's Flora/ covering portions of Washington and Oregon. 

 Unlike the great majority of manuals this one is devoted to an area 

 with natural boundaries on all sides save one — the north. It em- 

 braces the portions of Washington and Oregon which lie west of the 

 Cascade Mountains, and it does not include the Rouge and Umpqua 

 vallej^s in the latter state, where the flora is similar to that of northern 

 California. The flora of this heavily forested region is perhaps unique 

 in the fact that it possesses twenty-two species of coniferous trees and 

 only a single oak (except at its extreme southern edge). The well 

 known floristic poverty of coniferous forests, together with the fact 

 that this manual covers a natural and coherent area, makes the total 

 of 1617 listed species a surprisingly large number. This carefully 

 elaborated and well produced manual will replace the older Flora by 

 Thomas Howell, although it covers a slightly smaller area. — Forrest 

 Shreve. 



1 Piper, Charles V., and Beattie, R. Kent, Flora of the Northwest Coast. 

 Pp. 418, 191.5. Published by State College of Washington (.SI. 75). 



