Botany of the Morialta Reserve. 
By Professor J. G. Wood, D.Sc., Ph.D. 
JHIS short article is intended to serve as a guide to the chief 
types of vegetation which occur in the Morialta Reserve. 
Only those plants which characterize the different plant com- 
munities are mentioned ; however, these are sufficient to enable 
one to recognize the different types. A complete list of the flora 
is appended to these articles. 
To understand the vegetation of Morialta, it is necessary to 
gain some insight into the physiographic history of the Adelaide 
district. In Early Tertiary times the whole of what is now the 
Gulf Region of South Australia was probably an area of low- 
lying land, composed almost entirely of ancient rocks of Cambrian 
and Pre-cambrian age. During Middle Tertiary times this area 
was submerged and formed part of a shallow sea of great extent. 
At the beginning of the Pleistocene period (approximately one 
million years ago) great changes occurred in eastern and southern 
Australia. In particular, the Gulf Region as a whole was uplifted 
and at the same time, in the more unstable areas, great faults 
occurred and large blocks of land became depressed. These 
movements resulted in the Mount Lofty Ranges as we know 
them to-day, with their characteristic, step-like ranges, and also 
in sunklands which form the gulfs. 
The evidence indicates that the eastern portions of the 
Mount Lofty Ranges were uplifted earlier than the more western 
portions, for in the eastern areas rivers like the Torrens and 
Onkaparinga have wide, mature valleys, which suggests a period 
of comparative stability following the initial uplift. When the 
western portions of the range were slowly elevated, these rivers 
must necessarily cut steep gorges through the hills in order to 
preserve their valleys. When equilibrium was again reached, a 
drainage system gradually evolved and tributaries to the main 
stream developed. These are typical scarp-face streams with 
high grades, waterfalls, and steep-sided valleys. 
There are five such characteristic fault-face tributaries to 
the River Torrens. Where they join the Torrens on the plains, 
they are known as First, Second, Third, Fourth, and Fifth 
Creeks respectively ; in the hills corresponding names are Water- 
fall Gully, Slape’s Gully, Horsnell’s Gully, Morialta, and Monta- 
cute Creek. Each of these gullies shows considerable differences, 
due in large measure to the nature and bedding of the rocks. The 
rocks themselves are slates and limestones and highly meta- 
morphized schists and quartzites. 
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