SKETCHES OF THE COLORADO DESERT 129 



these render it probable that the seeds of them must have been 

 brought hither by the waters of the Gila or the Colorado Rivers. 

 Of these Leptochloa wibricata, Scirpus paludosus, Cyperus erythro- 

 rhizos, Scirpus speciosus, Rumex Berlandieri and Ammania Koeh- 

 nei probably came down these rivers originally, but at a period 

 so remote as to have long ago established themselves throughout 

 the delta. But the conditions indicate, I think, the direct and 

 immediate conveyance, by the floods of one or' the other of these 

 rivers to this bar, of the seeds of certain other plants which 

 were growing there. Of these I reckon Leptochloa fdiformis, Pan- 

 icum hirticaule, Eriochloa aristata, Eragrostis hypnoides, E. mex- 

 icana, Fimhristylis Vahlii, Nasturtium curvisiliqua, Physalis pu- 

 bescens and, probably, Orobanche californica. Other plants, of 

 wide Calif ornian distribution, were Typha latifolia, Petunia parvi- 

 flora and Pluchea sericea, an insignificant part of the total bar 

 flora. 



In February all these herbs had vanished, except Rumex Ber- 

 landieri, which was making a strong new growth, and the few 

 shrubs were flourishing. The loose silt in which these were grow- 

 ing made it easy to examine their root systems. The young wil- 

 lows had no tap roots, but five to eight nearly equal descending 

 rootlets, 8 to 10 inches long. Pluchea sent down a slender tap, 

 6 to 8 inches in length, from the lower part of which a few short 

 fibers were given off, while just below the collar started a cord- 

 like root, running 1 or 2 inches below the surface, and often more 

 or less exposed by the blowing away of the sand, which attained 

 a length of even 6 or 8 feet, and was almost wholly destitute of 

 fibers. 



These bottoms are the ancestral homes of the Yuma tribe of 

 Indians, and a large part of it is now set apart as their reservation. 

 Their houses, made of small tree trunks set perpendicularly in 

 the ground, the interstices plastered with mud, are hidden here 

 and there in the jungle. 



When first seen by the Spaniards the Yumans were an agricul- 

 tural people cultivating cotton, corn, beans, muskmelons, water- 

 melons and squashes. Cotton is no longer seen in the little 

 fields about their houses, but all the other crops are still grown 



THE PI-ANT WORLD, VOL. 17. NO. 4, 1914 



