ARID PORTIONS OF SOUTH AUSTRALIA. 77 



Among other species of the hill-slope habitat which occur rarely or 

 scatteringly, mention need be made of two or three additional ones 

 only. Thus, Cheilanthes ienuifoKa was found only among rocks, 

 south surfaces, on the northern slope of Table Mountain. Casuarina 

 lepidophloia occurs in small numbers around the south and west base 

 of Table Mountain (plates 11b and 12b), and also in few numbers 

 among the low hills on the Mount Series road. In other places, as on 

 the top of Table Mountain, the species occurs sparingly. This species 

 forms a small tree in the vicinity of Copley and is of some economic 

 use, making it probable that the number of individuals is very much 

 less now than in earlier times. It is to be questioned, however, whether 

 it ever occurred so abundantly at Copley as to constitute a pure com- 

 munity, as at Quorn, for example. 



An additional species which occurs but sparingly at Copley is 

 Pimelea microcephala. Two specimens of this small shrub were found 

 at the eastern base of the Mount Deception Range and in the same 

 habitat as Hakea leucoptera. It occurs in certain other places also, 

 as to the south of Table Mountain. 



Vegetation op the Washes. 



There is no sharp distinction between the plants of the hill-slope 

 habitat and that of either the plain or of other portions of lowlands, 

 provided the drainage is good. Thus there are lines of stress between 

 contiguous habitats where the species most characteristic of each are 

 more or less mingled. Some instances of invasion may be found, but 

 these appear to be rather uncommon. Inasmuch as the water rela- 

 tions of the washes of whatever kind are particularly favorable, this 

 fact is reflected in the vegetation growing in them. Thus, species 

 with large water requirements may be found in such a habitat, and as 

 a general thing, although not without exceptions, such forms have a 

 relatively large transpiring surface, may be of good size, and may 

 occur in abundance. 



One of the most characteristic trees of the washes is the red gum. 

 Eucalyptus rostrata. This becomes a fair-sized tree whose habit of 

 growth is illustrated in plate 13c. In places, as on Leigh's Creek near 

 Copley, the red gum is confined to the floor of the wash. Here the 

 bank is about 5 meters high and has all of the physical characteristics 

 of the plain of which it is a part. Somewhat farther up the same wash, 

 however, the transition from flood-plain to the adjacent higher ground 

 is gradual and the plant communities characteristic of wash and plain 

 are more or less mingled. Smaller contributing washes, whose depth 

 may be little if any over a meter and whose width may be no greater, 

 also carry the species. Such small washes are marked by a "single 

 file " of the gums crossing the plain. The same wash entering the hills 

 to the east of Copley is, with its smaller branches, likewise populated 

 with the gums. It is apparent, therefore, that the species is very 



