586 



3. THE COUNTRY AROUND TARCOOLA AND KINGOONYA. 



At about 324 miles from Port Augusta, near Wynbring, 

 tbe sandhills disappear and an undulating stretch of country 

 is entered upon, which continues to Kingoonya, At Tarcoola 

 there are some small hills, the sloping sides of which are 

 thickly strewn with rock fragments, about 4 in. square. 



III. Plants of the Nullarbor Plain. 



General. — There are two main types of plants at Hughes : 

 (a) shrubs of about 50 cm. in height, and (h) small herbs 

 and grasses. This formation was constant, as far as observed, 

 for 140 miles between Ooldea and Hughes. It was the result, 

 no doubt, of the uniform character of the surface topography, 

 soil, and rainfall. The shrubs include a very few tall ones of 

 Pttfospo/ffjiL 'phillyraeoide'i and Acacia tetragonojphylla, an-d 

 it is a remarkable fact that there are so few of them. 



The plants may be considered according to their height. 



1. The tallest plants were shrubs, 2 to 3 m. in height, 

 consisting of "dead finish," Acacia tetragono'phylla (only one 

 plant seen, 3 m. in height), and the ''Weeping Pittosporum,'' 

 P. philh/raeoides, of which only a few shrubs came under 

 notice. 



2. Tlie bluebush and saltbush shrubs varied from a half 

 to one metre in height, and were the dominant shrubs of this 

 vast treeless, riverless plain. 



3. The undershrubs and larger perennials and annuals, 

 of from 20 to 45 cm. in height, formed this third range of 

 plants, and consisted of species of Kochla, Bassia, Jilennodiay 

 Swainscma, composites and grasses. 



4. The ground flora of only a few inches in height was 

 represented by composites, and by Calandrinia, Dancus^ 

 Erodium, Euphorbia, Lepidium, Lotus, Nicotiaiia, Plantago, 

 Tetragonia, Crassula, and Zygophyllum species. This arrange- 

 ment, however, does not give the ecological relationships which 

 I wish to emphasize. 



Tlie following formations, which are of the open type, 

 were noted on the plain. 



Bluebush Fwrnation. 

 PI. xl., fig. 1. 



The Nullarbor Plain is not a dead level, but consists of 

 undulations, forming slight rises and shallow depressions, 

 varying from 1 to 2 metres. The bluebush (Kochia sedifaliaj 

 was not confined to either the rises or the hollows, but it was 

 noted that this shrub dominated an area of several hundred 

 square yards in extent. The saltbush ( Atriplex vesicarium) 



