Colin A. Taylor and Arthur A. Young, assisted by Dean W. Blood- 

 good, Dean C. Muckel , and Harry G. Nickle. In the Sacramento- 

 San Joaquin Delta, field work was under the supervision of the 

 late 0. V. P. Stout, assisted by Lloyd N. Brown. 



Obviously, it has been possible to study only a few of the 

 many species native to the West, partly on account of the diffi- 

 culties of transplanting or growing the larger types in tanks. 

 There are, however, a number of western moist-land species about 

 which a great deal has been learned, especially with regard to 

 their water habits and the quantity of water each will consume 

 under specified conditions. Plants growing in unusually moist 

 soil consume annually more than an average amount of water. In 

 desert areas, on the other hand, typical vegetation is adapted 

 to an extreme economy in its use of water. Between these two 

 types are many species that consume variable quantities depending 

 upon the supply available. It is apparent that there is seldom a 

 definite water requirement for most native vegetation. 



