PLANTS INTRODUCED INTO A DESERT VALLEY AS A 

 RESULT OF IRRIGATION 



S. B. PARISH 



San Bernardino, California 



A desert of an extreme type, the soil parched and bare of vege- 

 tation, or with stunted gray shmbs growing at wide inter\'als — 

 a land of desolation — such once was what is now the rich farming 

 country known as Imperial Valley. Situated on the southern 

 borders of the Colorado Desert, and depressed below the level of 

 the sea, it receives a precipitation so scanty and so irregular as to 

 be almost negligible in its effects upon plant life. Yet the .soil 

 itself, a silt deposited by the Colorado Ri^'er, is rich in all the 

 elements of fertility; only water was needed to cover it with 

 verdure. 



In 1902 this lack was supplied by the completion of an irriga- 

 tion system of canals and laterals, by means of which water from 

 the Colorado River was introduced and distributed over the valley. 

 As a result a compact bod}' of some 275,000 acres has been brought 

 into a high state of cultivation, highway's and railroads have been 

 constructed, and towns and villages have been built, with the 

 traffic and the intercourse of a busy population. It is a great 

 artificial oasis, bounded by the highline canals, beyond which 

 stretches the unreclaimed desert. 



With the entrance of man upon the scene, exercising his mral 

 and urbane activities, the entire en^-ironmental conditions were 

 changed. He speedily eradicated the sparse desert vegetation 

 and prepared a virgin field for his crops, with which appeared 

 their inevitable accompaniment — weeds — where before not a sin- 

 gle one had been able to intrude itself. As time goes on these will 

 be reinforced by new arrivals, so that it seems worth while, at this 

 early period in the history of the "\^alle3', to put on record a census 

 of its present constituents. Not alone will this be useful as afford- 



275 



