80 PLANT HABITS AND HABITATS IN THE 



Root-Habits of Plants op the Washes. 



A few root exposures were found along different washes, where the 

 erosion of the soil left them more or less in place. The leading results 

 of the observations on them can be briefly given. 



Pholidia scoparia has a large development of roots which take their 

 origin near the surface of the soil, and at less than 1 meter from the 

 main root they attain to a depth of approximately 40 cm. and maintain 

 this depth for an undetermined distance. There also is a well-marked 

 tap-root. Essentially the same condition was seen in Eremophila 

 freelingii, which was growing on the edge of a wash whose bank was 

 over 3 meters high. In this case, however, numerous radiating roots 

 were seen and no tap-root. The roots of unknown shrubs which were 

 growing along a smaller wash had roots of the same general type as that 

 given above for Pholidia. An undetermined species of Acacia was 

 found to have two prominent roots which were superficially placed; 

 the balance of the roots were not seen. The most deeply penetrating 

 tap-toot found was of an unknown Atriplex, which went to a depth of 

 about 2 meters. This species also had roots horizontally placed. 

 By a wash leading down from the Mount Deception Range there is a 

 small straggling grove of Eucalyptus oleosa where a few roots are ex- 

 posed. As the bank was not a high one the exposure was not extensive. 

 It showed, however, the swollen stem-base and enlarged root-crown, 

 "mallee" characters, and the origin of the main roots (plate 19b). 



It appears from these observations that the root-systems of peren- 

 nials of the washes and hill-slopes, with the possible exception of that of 

 Pholidia scoparia, consist of a deeply penetrating portion and a super- 

 ficial portion which extend in a horizontal direction. Obhgate deeply 

 penetrating or obligate superficial root-systems probably do not occur. 



Leaf-Fobm AND Leaf-Sizes. 



The leaves of all of the perennials observed at Copley are coriaceous, 

 and although they vary considerably in size they have a certain monot- 

 ony in outline. A few of the species have linear leaves, or phyllodia, 

 and these may be greatly elongated or they may be short and almost 

 spine-like. The widest as well as the longest leaves were those of 

 Eucalyptus rostrata, which may be characterized as being narrow 

 elongate. Thus, except for the juvenile leaves of this species, there 

 appears to be no perennial in the region with leaves that are even 

 ovate, not to mention the wider possible forms. 



A detailed account of the sizes and forms of leaves will be given in a 

 separate section. Here it will be sufficient to present a summary show- 

 ing the relative sizes of the leaves of several different species. The 

 leaves of Eremophila alternifolia are given a value of 1 ; from this as the 

 base, the relative size (area) of the leaves of several species is as fol- 

 lows: Acacia aneura, 1.3; Eremophila brownii, 2; Myoporum platycar- 



