MOVEMENTS OF VEGETATION IN THE SALTON SINK. 145 



nearly similar to the conditions on the shores of the Salton as to make the results of direct 

 value in a discussion of the action of the species treated on the shores of the lake. 



Seeds of species which would represent the main features of the occupation of the 

 beaches and also the principal anatomical types were procured, and these were thrown 

 into dishes containing about 400 c.c. of Salton water, after which a loosely fitting cover 

 was provided to prevent evaporation and consequent concentration of the solution. 



After standing for some time, the water would be poured off and a new filling would 

 be made in order that the effects of heightened concentrations might not introduce a vari- 

 ation into the results. The preparations were examined at intervals of a day or two during 

 the first two months, and each time the beaker would be lifted from the table and shaken 

 violently to simulate disturbances of the water due to wave-action. It was realized that 

 this did not give the entire effect of disturbances of the lake where the wave-action might 

 continue for a week without intermission. On the other hand, the shaking resulted in 

 many instances in sending numbers of seeds to the bottom which had been buoyed by 

 adherent bubbles "of gas attached to their coatings, and while some of the seeds probably 

 floated a few days longer in the experimental vessels than they would have done in the lake, 

 yet the prolongation was probably not more than one day in ten. 



Amaranthus palmeri is a rapidly growing plant of short cycle and widely varying 

 habit. It may reach maturity with a short unbranched stem a few inches in length, while 

 on the other hand great branched stems may reach a height of 6 feet in the summer in the 

 Delta lands of the Colorado. Here it is known as " quelite," and the green stems are eagerly 

 eaten by grazing animals. The Cocopah Indians collect the seeds in late summer and pre- 

 serve them to be used as food in the winter. The interrupted flower spikes terminate 

 the stems and branches and the indehiscent utricles hold the seeds so that they are cast 

 from the plant during an indefinite period. The shining dark lenticular seeds are not over 

 0.8 mm. in diameter and less than half this in thickness, with an average weight of 0.3 mg. 

 100 seeds were thrown into a beaker of Salton water on November 16, 1912. The vessel 

 was shaken daily at each examination and a few would go to the bottom, with the result 

 that by January 10, 1913, all but one had sunk. The rising temperature started imbibi- 

 tion with the result that swollen seeds were brought to the surface, being buoyed by gas 

 formed by the end of January (January 25). A week later three seedlings were floating 

 and two more were seen on February 17. The total number of germinations reached 

 seven, and the seedlings had a combined length of root and hypocotyl of over 2 cm. 

 As these seemed to come to a standstill all were "stranded" on March 10. 



• Amaranthus was found on the muddy shores of Obsidian Island and Imperial Junction 

 Beach in 1908 and 1909. Its failure to appear later can not be connected with anything 

 except the increasing salinity of the water. Although germinations ensued in Salton 

 water of June 1912, yet the proportion was very small and the development definitely 

 limited, while the stranded plants failed to survive. The flotation period of the seeds, 40 

 to 50 days, was one which would allow it to be carried long distances by water. Its small 

 size and weight would likewise render it liable to be carried by birds or winds. The actual 

 locations of the individuals in the filled washes and on the shores was highly suggestive 

 of flotation. 



Atriplex fasciculata is abundant in the Salton region, where it forms a small shrub, 

 reaching a maximum height of 2 or 3 feet on various beaches. It is native to the higher 

 parts of Big Island and Obsidian Island as well as of the slopes about the lake, and was 

 a prominent feature of the first group of species appearing on emersed beaches. The 

 germination of seeds within a few feet of the margin of the water suggests that the fruits 

 might have floated to the place or have been carried there by birds, although no actual 

 tests could be made which would offer evidence on the subject. It is probable that the 

 species, like A. canescens, may survive progressive desiccation to the general condition 



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