130 S. B. PARISH 



by them. Their clearings afforded an interesting study in weeds. 

 For the most part these were native plants, Amaranthus Palmeri, 

 robust, and sometmies more than 6 feet high. Aster spinosus, a 

 most obnoxious weed, and Leptochloa ivibricata, the three in about 

 this order of frequency. The weeds of cultivation which are 

 most common in other parts of California were here conspicuous 

 by their rarity, or. oftener by their entire absence. There was 

 much Bermuda grass, and some purslane, but the abundant 

 cockleburs of southern California, Xanihium canadense and X. 

 spinosum, were here replaced by two other species, X. struma- 

 rium and X. commune, both plentiful, and not known in the state 

 except in the delta region. Perhaps other Californian weeds 

 might be discovered by a more prolonged search, but they can 

 hardly be abundant. The isolation of the region, separated by 

 two hundred miles of desert, has so far protected it from the nox- 

 ious immigrants that have so successfully established themselves 

 in the state. It will be of interest to observe how long this im- 

 munity will continue under the changed conditions that must re- 

 sult from the u-rigation, and consequent cultivation and settle- 

 ment, of the great areas of hitherto desert lands which are now 

 in process of reclamation. 



