ARID PORTIONS OF SOUTH AUSTRALIA. 71 



hollows made possible relatively favorable water conditions, with 

 results which can be briefly given. 



In one place the roots of several annuals, mainly of species I did not 

 know, were examined. The shoots were 2 to 7 cm. long and for the 

 most part either in flower or in fruit, and therefore fully matured 

 specimens. A cruciferous species had a tap-root which varied in length 

 from 4 to 8 cm. Another species, with a rosette, had a prominent 

 tap-root 7 to 9 cm. long. Of all the annuals seen at this place none 

 had roots which penetrated over 12 cm. 



In another locality, about 2 miles east of Copley, but on a sloping 

 plain, the roots of several annuals were dug up. Among these were 

 several specimens of Zygophyllum crenatum. In specimen a the shoot 

 consisted of 4 leaves and was 6 cm. long, and the tap-root was found 

 to be 8 cm. in length. It was little branched. In specimen h the shoot 

 bore 6 short leaves and was 4 cm. in length. The tap-root was over 

 13.5 cm. long. Specimen c had a tap-root over 8.5 cm. in length. 



Roots of Geranium pilosum, which is one of the most common annuals 

 on the plain, and which was growing abundantly near the Zygophyllum, 

 were also examined. In specimen a the small rosette had 7 leaves 

 and flowers had been formed. The leading root was a tap-root, but 

 this bore numerous fine laterals. It penetrated to a depth of more than 

 8.5 cm. In specimen b the shoot was somewhat larger and the tap- 

 root was traced to a depth of over 11 cm. In another situation, where 

 the plain was in part bare but where there were also slight and in- 

 conspicuous hollows, there was a sparse growth of annuals. These 

 were of various species, including an undetermined grass about 3 cm. 

 high, a species of Geranium, a Zygophyllum, and some crucifers. As 

 a rule the shoots of the annuals, which were fully matured, did not 

 exceed 4 cm. in height. Although there was found to be a certain 

 specific difference in the root-systems of these plants, it was learned 

 that in no case did the penetration exceed 13 cm. and it was mostly 

 less. In the case of the Zygophyllum, prominent laterals 8 cm. long, 

 more or less, were found. 



As a result of the observations on the winter annuals of the Copley 

 Plain, it can be said that, even under such relatively favorable local 

 water relations, the roots do not penetrate the ground over 10 to 13 

 cm. and for the most part they lie closer to the surface than this. 



The roots of species of Atriplex and of Kochia, which were also 

 situated on the Copley Plain, were examined in several specimens, 

 and a certain parallelism in development was noted, similar to the 

 development of the root-systems of most perennials, other than 

 halophytes, which were seen. One of the features of the plain referred 

 to is the presence of various dead perennials, mainly halophytes. 

 Whatever may have been the cause of the death of the plants, it was 

 noted that the root-system remained almost intact. The roots of 



