1936] MAMMALS AND LIFE ZONES OF OREGON 17 



in flavor but not unpleasant in taste and are generally eaten to some 

 extent by sheep and other stock. The bushes are so very spiny, 

 however, that only the tender tips are browsed off. Many other 

 plants are wrongly called greasewood where the true Savoo$atu8 does 

 not occur, but the name should not be used for any other bush. 

 Dondia, or Suaeda, and Salicornia (samphire) are closely related to 

 the greasewood and have somewhat the same habits. They are even 

 more addicted to salt and alkaline ground and even more strongly 

 impregnated with salt and soda. 



The saltbushes, several species of shrubby Atriplex including 

 canescens, confer tifolia, patwa, nuttallii, and a number of herba- 

 ceous species, are generally common over the desert Sonoran valleys 

 and in places give a dominant character to the low vegetation. They 

 generally indicate the presence of a little salt or alkali in the soil, 

 and the leaves have a not unpleasant saline taste. Generally they are 

 good forage plants and hence are often entirely eradicated over val- 

 leys that are overgrazed. A. confertifolia with its abundant spines- 

 cent twigs is the least likely to be destroyed by overgrazing. 



Woolly sage, the beautiful silvery white little shrub, Eurotia tanata^ 

 called by the sheep herders " winterf at ", is one of the most valuable 

 forage plants of the desert. Being so desirable as winter forage and 

 so unprotected it is practically exterminated over most of its range, 

 except at such long distances from water that stock cannot get to 

 it 



A few scrubby junipers are found in the canyons and on steep 

 slopes but rarely in extensive stands where accessible for ranch use. 

 Their shade is often grateful and their fragrant wood is prized as 

 camp fuel in the foothills and rim-rock canyons (pi. 8). 



Weeds, those hobos of the plant world and the pest of the farmer, 

 have few friends or defenders. Out in the deserts of eastern Ore- 

 gon, however, they seem to have found a use. Where sheep have 

 eaten everything but the lava rocks and killed out all the native 

 plants, even the sagebrush and cactus, the little exotic mustards, 

 chickweeds, pennycress, tarweeds, prickly lettuce, foxtail, and brome- 

 grass have volunteered to clothe the nakedness of the soil and in many 

 places have bravely succeeded. Over great areas the little seeds of 

 these weeds are the only available food for pocket mice, kangaroo 

 rats, and other small rodents. These plants, too, are the principal 

 food for thousands of sheep. 



In 1927, in Klamath Valley the county agent reported a flock of 

 100,000 sheep, pastured all summer entirely on foxtail and China 

 lettuce, that yielded thousands of fat lambs for market. The cash 

 value of weeds' to eastern Oregon would amount to a high figure if 

 it could be estimated, although insignificant compared with the value 

 of native vegetation destroyed by overgrazing. 



CROPS FOR UPPER SONORAN ZONE IN EASTERN OREGON 



While arid and much of it unsuited to agriculture because of rough 

 surface or lack of available water, eastern Oregon contains many 

 extensive valleys of rich, mellow soil, with ample water supply for 

 local irrigation. The Columbia Kiver Valley, including the Des- 



7209 36 2 



