44 



phylll and Horaalobi. 



The Oregon-Washington coast region is a normally forested area 

 with no distincitve flora and no Astragaline importance. 



The Siskiyou region of southern Oregon is a very small and iso« 

 lated area caused by barriers and rather low humidity but not worth 

 any special treatment here. 



The Great Basin region belongs with the Pacific group and is 

 easily separated into the Bonneville and Lahontan. or the eastern and 

 western part, embracing the area that does not drain to the Colorado 

 or the Columbia. It is a high plateau region with parallel mountain 

 ranges about a mile high every twenty miles and running north 

 and south, bounded on the north by the low sagebrush and juniper 

 hills of the Columbia drainage, on the east by the lofty Wnsatch 

 range and its Wasatch Plateau extension at the south, on the south 

 by no bnrriers but the Troi)ical climate of the Colorado and on the 

 west by the Sierras. The flora is quite different from other regions. 

 There i-; much intergrnding at the north, some at the east and w-est 

 and little at the south. 



The annual temperature ranges from '}?> degrees to 50 desrrees 

 on the floor, the humidity from 25 per cent to 49 per cent, and rai-^fall 

 from 6 to 12 inches on the floor. The soil is gravelly, with very 

 little sand, and there are wide areas in the centers of the valleys with 

 alkaline clays. There is no river system except the Humboldt on 

 the west and the Jordan, Sevier, and the Bear on the east. It is a re- 

 gion of scattered springs and short sinking streams. The upper Snake 

 river region has much in common with the Great Basin but really be- 

 longs in the Columbia drainage. . Its flora has a few peculiarities. 



The Bonneville section is characterized in its Astragaline flora by 

 me great development of the Argophylli, to which its soil and e"- 

 vation are peculiarly adapted. The alkaline areas have few s^ec'es 

 A. Toanus being about the only peculiar species, though A. tetrap- 

 terus ero-^'s where there is a little alkali, A. Wardii and serpens 

 Ere other peculiar species of the Sevier region. The Lahontan sec- 

 tion is characterized by an excessive development of the Podo-sclero- 

 carpi in the alkaline part, such as A. Serenoi, a canonis, pterocarpus, 

 Casei: the Malaci occur on the gravelly mesas, also Andersoni. Gib- 

 bsii, etc. 



The Mojave-Cclorado river region from Springdale Utah to the 

 Sierras and southward to Mexico contains a peculiar florn. with ni'vuy 

 local branches and yet all are connected in a general whole hard to 

 separate. The region is one of great temperature and mininnm hu- 

 midity and almost no rainfall. Its flora appears only in the spring 

 and often for years at a time does not develop at all worth mention. 

 Each subdivision of the region has a few. prselongus, forms of lenti- 

 pinosus and amphioxys, Laynese, Zlonis, remulcus. The Amargosa 

 Desert-Death Valley region has A. Mohavensis. albens, Panaminteu^is, 

 triquetrus, acutirostris. The Mojave-Salton Sink region has A. lima- 

 tus. Vaseyi, aridus, Thurberi, Palmeri, etc. The soil of this region 

 Is almost wholly sand. There are many forms of A. lentiginosus, and 

 other more widely distributed species. 



The Arizona-New Mexican floor has a similar climate to the above 

 but very different in the summer and fall rains which clothe the 

 plains with verdure. Many species of Astragalus grow there, but 

 few are local. We have A. nothoxys, Arizonicus, tephrodes, etc. The 

 soil is mostly sand on the floor and gravel on the slopes. This belongs 

 to the fourth grand division. 



The Texan plains belong in the same division of fall rains and 

 have a number of peculiar species, mostly annuals, such as A. lepto 

 carpus, Lindhelmeri, Brazoensis. reflexus, giganteus, Wrightii, etc. 

 The Mexican Plateau is also a division of fall rains and has ?n- 



