^,jj- INTKODUcrriUN. 



two thousand, and it was thought that the work of doteiiniuing and describ- 

 ing them would not occui)y more than a year or two. Tlie co-operation nl 

 distinguished speciahsts throughout the country was secured, and various 

 l)ortions of the coUections ])lacetl in tlieir hands to he worked up. It 

 is, however, at the Herbarium ol' Harvard University, and under the 

 supervision of Professor A. Gray, that most of the material has thus iar 

 been elaborated. The collections made by the Survey were there arranged 

 by Professor Hrewcr, and the new spiicies of the I'oli/pdalw and Gamo- 

 2)etalcc were described by Professor Gray in various connnunications made 

 to the American Academy of Arts ami Sciences, and published in their 

 Proceedings.* 



In this work it was necessary that the material which had accumulated 

 during the many years in which California had been botauically explored 

 by various Government expeditions, both American and foreign, and by 

 numerous private collectors, should be juissed under review. It was ecpialiy 

 necessary that the mass of literature already accunuilated in relation to this 

 Flora, and scattered througli hundreds of volumes, which in many cases are 

 not to be obtained e-xce^it with great ditUculty, should be thoroughly ex- 

 amined. Much the largest portion of this mateiial, both of hooks and 

 plants, was accessible at the Herbarium in Cambridge; and, where the collec- 

 tions in this country were di!licient. both Dr. Gray and Dr. I'lngeimann were 

 enabled to supply deficiencies and make the necessary comi)arisons, during 

 visits to Europe, and especially to the great storehouse of tlie world's 

 botany at Kew. AVhile this work of description and comparison went on, 

 much new material was constantly coming in, chiefly through several zeal- 

 ous private collectors, who of course had to send their jdants to C^ambridge 

 for determination. Thus it happened, that, as the amount of material to 

 be worked over was constantly increasing, so the time recpiired ior the wcnk 

 was also greatly expanded. The Survey not being able to pay any one lor 

 devoting his whole time to this investigation, the year 1874 had been 

 reached and the iniuting had not been begun. The Legislature of 1873 - 74 

 put an end to the work by refusing any further ai)propriations for the 

 Survey, and the present volume would have remained unpublished, had it 

 not been for the generosity of a few citizens of San Francisco, who came 

 forward and jilaced in the hands of the late State Geologist a sum sullicient 

 • Sec I'loceediiigs Am. Acad. Vol. VI. 51S), uiul Vll. 327. 



