170 THE SALTON SEA. 



while between 1 5 and 20 examples of Spirostachys were scattered over various emersions, 

 their age suggesting germinations during 1912 or late in 1911. Six species were thus 

 seen to be present, with a total representation of about 30 individuals, and plants of 3 

 of the species were mature and either were fruiting or had done so; 2 of the 6 were 

 compositaceous with fruits abundantly furnished with pappus. It would seem probable 

 that these two species were carried here by the wind. The seeds of Atriplex lentiformis 

 germinate very quickly after being wetted, but the plantlets are capable of floating for 

 periods of several weeks. The occurrence of the four individuals seen here might well be 

 attributed to such action. The fruits as noted (see page 146) are fairly large and are not 

 so readily carried by either birds or the wind as some of the others. The minute seeds of 

 Sesuvium float for two or three weeks after falling in the water, and the seedlings rise to 

 the surface and are capable of flotation for extended periods. Seeds of this size are also 

 very liable to be carried about by violent winds, while they readily adhere to any object 

 thrust in the water in which they are floating and might well be carried to the island by 

 any one of the methods mentioned. The seeds of Heliotropium might likewise be carried 

 about by several agencies, although it is to be noted that despite the enormous number 

 of seeds and the abundance of the opportunities only two individuals of Sesuvium and of 

 Heliotropium grew on the island in six years. This, however, would be a very brief period 

 in the conditions of transportation of a species to new lands in practical geographical work. 

 Spirostachys is also subject to the conjunction of many conditions which might bring it 

 to the island, but the appearance of young plants far above the present level of the water 

 suggests that the seeds were carried to the place either by winds or birds. The indefinite 

 retention of the seeds on the parent plant, making a crop which falls to the ground over a 

 long period, furnishes material which might be acted on by either of the agencies mentioned. 

 The positions of the young plants render of comparatively little importance the fact that 

 the seedlings are capable of flotation for an extended period. All of the species mentioned 

 were also present on the beaches of Obsidian Island, 2 miles to the southward, and also 

 on the smaller islands to the southwestward, described below. 



Immediately after the examination of Cormorant Island in November 1908, a visit 

 was made to a small island which had risen above the surface or rather had been laid bare 

 at some time late in 1907 or early in 1908; a sand bar, barely above the level of the water, 

 now ran from it to the larger land mass, but had not been bare long enough to figure in 

 the history of the pioneer species which must have reached the place several months earlier. 

 Many square yards of sandy and gravelly soil furnished suitable conditions for germination, 

 while the higher part of the emergence consisted of a lot of blocks of Obsidian, some a 

 meter in diameter, which would have served very effectually in causing the deposition of 

 wind-borne seeds. A single plant of Sesuvium in bloom, Heliotropium also in bloom, 

 Pluchea camphorata, Spirostachys, Parosela emoryi, Atriplex lentiformis (?), and single plants 

 of two unrecognizable species were present. A second small island to the westward and 

 south of Big Island showed a surface consisting of extremely rough and broken rock masses 

 with small level pockets of moist soil, bearing a few plants of Pluchea sericea, Sonchus 

 asper, Heliotropium, Atriplex lentiformis (?), and Eclipta alba. These islands were much 

 frequented by pelicans and cormorants nesting among the rocks. The considerations 

 noted above apply to the presence of the same species here. Eclipta probably floated to 

 the place, and Sonchus might have been carried by the wind; the position of Parosela on 

 Obsidian Island (as described previously) suggests flotation, but nothing in its location 

 here could be taken as evidence of the manner in which it had been carried to the spot. 

 This would apply also to the unknown species. 



These islands were visited again a year later (October 1909) and showed only Pluchea 

 camphorata, Spirostachys, Sesuvium, Heliotropium, Atriplex, Scirpus paludosus, and Pluchea 

 sericea; from which it is to be seen that Sonchus, Eclipta, and the two unknown species 



