^2 



BOTANICAL GAZETTE 



[JULY 



by a succession of low mountain ranges, such as the Agua Dulce, 

 Pinaeate, and Santa Clara Mountains. The soil is particularly sub- 

 ject to the action of the wind, but the irregular consistency of the 

 sand allows the formation of moving dunes or "sables" in a few 

 localities only near the delta. Mounds of a few meters in height, 

 held together by the roots of Ephedra, Covillea, and other shrubs, 

 are numerous, however, such mounds being due either to the erosion 

 of the soil around them, or to its accumulation and retention by the 



Fig. 4. — View in Salton Basin, California; the suiface of the soil is thickly incrusted 

 with saline matter in the open spaces; the vegetation consists chiefly of Spirostachys 

 and Atriplex. 



clumps of plants. In addition to the few herbaceous annuals which 

 arise during the season favorable for growth, the principal types are 

 perennials with spinose branches and reduced deciduous leaves, 

 although a few species with hardy leaves are included. Ephedra, 

 Gaertneria albicaulis, Oenothera elavijonnis, Lupinus mexicana, 

 Abronia villosa, Astragalus Vaseyi, Plantago scariosa, Langloisia 

 Schottii, Stillingia annua, Asclepias subulata, and Fouquicria splen- 

 dens are typical examples; while a few forms with deeply lying bulbs 

 arc also found here, including Hesperocallis Montana (fig. 5). 



