THE VOICE OF THE DESERT 



120 



worms dominant you must go south of the Mason and 

 Dixon Line. During the century just past, the winkle, be- 

 loved of cockneys, has invaded the Atlantic Coast. 



Since the true desert areas constitute a very special and 

 difficult environment, they are not readily colonized and in 

 Arizona few if any plants except those under cultivation 

 were intentionally introduced by man. Every conspicuous 

 feature of the desert landscape has been there for a long, 

 long time slowly adapting itself to heat and aridity, either 

 here or in some other not too distant desert from which it 

 could spread without the necessity of passing through any 

 region unsuited to it. The vast majority of the nearly two 

 hundred introduced plants counted in the flora of the state 

 grow principally either in the portions not naturally desert, 

 or in the neighborhood of houses or cultivated fields where 

 conditions have been mitigated. 



There is, however, one interesting exception which hap- 

 pens to be of some economic importance and is found 

 everywhere on plains and mesas if not in full desert. Cattle- 

 men have a popular name for it and call it "filaree," a word 

 corrupted from the Spanish, and they are well aware of the 

 plant because it is green in midwinter and is eaten by their 

 herds when little else is available. I have found it bloom- 

 ing in January about my house in places where enpugh 

 water is spilled to make the difference between natural 

 desert and the slightly moister conditions of the mesas. It 

 is believed to have been accidentally introduced at a very 

 early time by the Spanish settlers, but it is really a Euro- 

 pean member of the wild geranium family. 



The question how and when species were unintention- 

 ally introduced is quite as interesting as the question where 



