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C N T E N T S 



Page. 



Introduction 9 



The b.;tanical explore: s of Washington 10 



Menzies - H 



Lewis 11 



Douglas - 12 



Scouler - , 13 



Tolmie 14 



Gairdner 14 



Wyeth .._ 14 



Nuttall 14 



Pickering and Brackenridge - 15 



Geyer 16 



Spalding 16 



LyalL... 16 



Jefierey 17 



Cooper , 17 



Collectors since 1860 17 



Physiography and geology - - 20 



The Pacific Coastal Plain - .--- 30 



Th3 Olympic Mou tains 21 



The Puget Sound Basin 21 



The Cascade Mountains 22 



The Okanogan Highlands 24 



The Columbia Plains 24 



The Blue Mountains . -- S6 



Climate 26 



Precipitation . - - 26 



Sunshine and cloudii-es^s . - _ 29 



T mperature - - 30 



Western Washington 30 



Eastern Washington ... 31 



Winds ..-.- 32 



The Zonal distribution of Washington plants 33 



Upper Sonoran life a: ea 36 



Origin of the Upper Sonoran flora 37 



Humid Ti ansition area - - 40 



Uplands 41 



Bottom lands -. 42 



Gravelly prairies -.- 43 



Seashores i 45 



Sphagnum bogs .' _ - - 46 



The Coastal strip 46 



Arid Transition area 47 



The Bunchgrass prairies . 48 



The Yellow Pine forests 50 



7 



