98 THE AMERICAN BOTANIST 



near one another that their branches intermingle and as these 

 are armed with formidable thorns the result is a thicket as 

 dangerous to flesh and clothing as a cactus jungle. 



The family relationship of the mesquite is with the peas 

 and beans, a fact less evident from the rather inconspicuous 

 greenish-yellow flowers that appear in spring than from the 

 bean-like seed pods with which the little trees are later abund- 

 antly adorned. These pods contain a sweetish-sourish pulp 

 when mature, but to the desert dweller their chief value is when 

 they are dried. They then make a valuable fodder for horses 

 and cattle, while the seeds themselves if ground make a nutri- 

 tive meal for human food, as the older generation of Indians 

 well knew. 



Of the same family but very different in appearance is the 

 small tree Dalca spinosa. With thorny, almost leafless 

 branches, it is likely to be passed by the traveler as dead or dy- 

 ing, unless the time be early summer, when it presents a sight 

 he is not likely to forget. It is then covered with myriads 

 of purple pea-like blossoms all the more remarkable because of 

 the hot, parched waste in which the tree grows. I seem to re- 

 member having seen this desert denizen listed in some nursery- 

 man's catalogue, and it may be that it has been introduced 

 into cultivation. It is certainly worthy of a place in any gar- 

 den, though how it would grow under other conditions than 

 those of its desert home, I do not know. Plants accustomed to 

 the excessive dryness of the desert air will often start well in 

 moister surroundings but are very subject to the attacks of 

 scale and other insect pests. 



Other trees of this desert of southeastern California are 

 the so-called desert willow (Chilopsis saligna) with a willow- 

 like aspect and whitish mottled flowers like catalpa to which it 

 is of kin, and the palo verde (Parkinsonia Torreyana). The 

 latter, as the Spanish words of its name indicate, is indeed a 

 green tree — green from base of trunk to tip of the highest 



