BIOLOGY OF SNOWY RIVER AREA 147 



which can be described as volcanic agglomerates whilst others 

 are true quartz porphyries; in places they are many hundreds of 

 feet thick. Underlying this is granite, which outcrops in some 

 areas. There are also exposures of Ordivician, isolated small 

 outcrops of basalt, and, to the south, some limestone. The steep 

 mountainsides hold practically no soil and there is little alluvial 

 deposition in river valleys. 



The bare country absorbs little of the rainfall, which averages 

 30 inches per year, and the run-off causes a very rapid change 

 of river rise and fall which is accentuated at the time of melting 

 snow. 



The northern slopes of the mountains are dry and open; the 

 southern slopes are less dry and carry more scrub. In the high 

 country (4,000 to 5,000 feet) there are large areas of Snow Grass 

 (Poa caespitosa) and stands of Snow Gum (Eucalyptus pauci- 

 flord). The northern lower slopes carry White Gums (Euca- 

 lyptus viminalis and E. rubida) and Box (probably Eucalyptus 

 albeus), and have little or no ground cover though some areas 

 have a sparse growth of the low-growing Tea Tree (Leptosper- 

 mum attenuatum >. The principal tree on the southern slopes 

 is the Woollybutt (Eucalyptus gigantea). Still lower in the gullies 

 is a varying amount of scrub including Blanket-leaf (Bedfordia 

 salicina), Musk (Olearia argophylla), and several species of Tea 

 Tree (Leptospermum lanigerum, B@ckea Ghirmiana, and Kunzia 

 pedunculans). In the deeper gully-heads, the scrub thickens to 

 jungle proportions, and besides Blanket-leaf and Musk contains 

 Lilly-pilly (Eugenia Smithii), Wire Grass (Tetrarrhena juncca) 

 and Lianes including Clematis (Clematis aristata) and Supple- 

 jack (Lyonsia straminea). 



Such a short, generalized outline of the country must neces- 

 sarily leave many gaps, but is intended to present only an overall 

 view' which, as specific localities are more intensively worked, 

 may lie tilled in. 



PLANTS COLLECTED 



We are indebted to Dr. R. T. Patton, Melbourne University, 

 for the identification of botanical specimens. 



Family GRAMINEAE 



Genus POA 

 Poa caespitosa G. Forst. 

 Wombargo Tableland, 5,000 feet. 



