SKETCHES OF THE COLORADO DESERT 127 



plex. The prevalent species are Atriplex lentiformis and A. poly- 

 carpa, but there is considerable A. canescens. They grow as 

 high as 8 or 10 feet, and their innumerable branches are inter- 

 locked and dense as a hedge, so that it is impossible to force one's 

 way through them. They are much overrun by a variety of 

 Philaberiia linearis, an Asclepiadaceous vine, which grows here 

 unusually stout and vigorous. In early November this was 

 spreading over the shrubbery fleeces of glistening whiteness, shed 

 by the bursting pods. The only other shrubs were Pluchea seri- 

 cea, gregarious and abundant, and an occasional Lycium Torreyi. 



On the Ai'izona side of the river a range of low hills, on which 

 the town of Yuma is built, comes down to its very brink. Oppo- 

 site, on the California side, rises an isolated bluff of quartzose rock, 

 some two hundred feet high. The tawny river washes its base, 

 and a few stunted larreas cling to its crumbling sides. Hither 

 came, in 1780, Padre Garces, and on its summit founded his ill- 

 fated mission of La Purissima Conception, the first lodgment of 

 white men on the banks of the Colorado. Long afterward it be- 

 came the site of Fort Yuma, and now is occupied as a govern- 

 ment school for Indians. 



It seems strange that the river should flow through the narrow 

 chasm between these two bluffs, there being in rear of the Fort 

 a mile or two of low alluvium, where it might easily cut a more 

 commodious passage. In fact, it does overflow some part of 

 these flats in time of high water, and through them there is a 

 channel, which then carries a part of the floods. 



In November some of the depressions of this old channel still 

 retained large pools of water, which the settling of the silt had 

 left clear. From the shallower hollows the water had evapor- 

 ated, leaving beds of earth which were still moist. Around the 

 ponds, and in the damp basins, grew many interesting plants, 

 not found in California except in the delta. Among these may 

 be enumerated Leptochloa imhricata, Scirpus paludosus, Cyperus 

 erythrorhizos, Rumex Berlandieri, Sesbania macrocarpa, Ammania 

 Koehnei, Physalis lanceifolia, P. Wrightii, Lippia nodiflora, Ec- 

 lipta alba, and Aster spinosus. Plants of wider Californian dis- 

 tribution were Phragmites communis, Sesuvium sessile, Euphorbia 



