INTRODUCTION 



r I ^IIE Act of the Legislature, jiassed iu 18G0, autliorizing a geological 

 Survey of the State of California, required, among other things, a " full 

 and scientific description of its botanical productions." In accordance with 

 this requisition, the material necessary for such a description was assiduously 

 collected by the Geological Corps, whenever and wherever it was possible 

 to carry on this work in addition to the other more pressing duties of the 

 Survey proper. During the years from 18G0 to 18G4, the botanical collect- 

 ing was entirely under the charge of, and mostly performed by, Professor 

 W. II. I'rewer. It was under his supervision that the bulk of the material 

 was accuimdated, llu^ (diiboriition of whic^h has fornuMl the basis of the 

 present volume. Professor l>rewer having left California in 18G4, no I'arther 

 continuous and systematic collecting was attempted by the Survey. Mr. 

 H. N. P)()lander was, however, engaged for a few months in 18GG and 18G7 

 in making a more thorough botanical ex])loration of portions of the Sierra 

 Nevada than liad before been i)ossible ; and he also made a trip through the 

 Coast Panges, north of the I'ay of San Francisco, in which he wa.s assisted 

 from tlu^ funds of the Survey, then, as nhvays, entirely iiifideiiuale to a 

 vigorous prosecution of the work in all its l)rnnches. Dr. J. G. Cooper, 

 Zoological Assistant of the Survey, during a winter spent at Fort Mohave, 

 and on the way thither and back, made important additions to the botanical 

 collections. On the return of Professor Brewer to the East, in 18G4, an-ange- 

 nients were commenced for working up the collections, with a view to the 

 publication of a Flora of Californiu, or a systcmali-; de.'^cription of the plant^s 

 growing spontaneously over that wide area of between ir.0,000 ami 1GO,000 

 square miles.* The total number of species thus included was estimated at 



• In jioiiitof fact, in tlie pn'sont volume tlio hntftny i>t' tlic wliolo ea.stciii .vloi)0 of the Sicrm 

 Nevmlii, nn<l of thn ranges adjacent to it on the civst, from Arizona to Nortlicrn Nevada, nnd 

 of Soulliern Oregon, lia.s l)een fully worked up, nnd n considerable nunil>er of sjiecies included 

 which have not yet been found within the borders of the State of California, although many 

 of them, in all probability, will be. 



