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260 BOTANICAL GAZETTE. [ October, 
are narrow, very rarely with an acre of interval or surface 
approaching to a level, the sides sometimes rocky or pre- 
cipitous, more frequently sloping to the summits of the lateral 
ridges. With few exceptions, also, these mountains are for 
most of the year destitute of water, with but small rivulets in 
‘**No portion of this district, however des- 
ert in repute and in fact, is destitute of some amount of veg- 
etation, even in the driest seasons, excepting only the alkali 
flats, which are usually of quite limited extent. “Even these 
have frequently a scattered growth of Sarcobatus or Halo- 
stachys surmounting isolated hillocks of drifted sand com- 
pacted by their roots and buried branches.’’ With these in 
alkaline soils are usually combined several other Chenopodi- 
aceous plants, such as Salicornia herbacea, several species 
of Sueda, Kochia prostrata, Eurotia lanata, Grayia polygal- 
thraea Nuttallii, and of grasses chiefly Distichlis maritima, 
Spartina gracilis and Sporobolus asperifolius. There is 40 
almost universal absence of trees. In the valleys of 
smaller, Artemisia trifida. These are often accompanied Dy 
Bigelovia graveolens, called broom-sage, and Tetradym 
canescens, and along the fresh water streams two species © 
' shrubby willows. On the foot-hills only is found the shrubby 
