590 



Billardieri formed tall shrubs and was often seen among 

 acacias. In the wade open flats, between some of the smaller 

 sand ridges, were seen shrubs of Crafistt/lis conocejyhala and 

 Westringia Dampieri, var. rigid a, and Bassia echinojinila 

 was associated with them. Two other shrubs, Cassia eremo- 

 pkila and C. Sturtii, were fairly common in the sandhill 

 region, with Dodonaea attenuata as a rare species. 



The Ground Flora. — By the ground flora is meant the 

 undershrubs and annuals which range from 2 to 25 cm. in 

 height. The dominant species were Cephalipterum Drnm- 

 mondii, Waitziu ami'tninata, and Helipterum florihundum ; 

 they are annuals and grow in open association. Some plants 

 preferred the sand ridges (often in the open and seldom in 

 the shelter of other larger plants), viz., Waitzia acuminata, 

 CalandHnia disptrtna, Stackhousia muricata, Podotheca 

 angustifolia, and Ponnax umhellata. The latter species, and 

 the Stackhousia, developed a long slender tap-root which, 

 no doubt, penetrated the loose sand to the moisture below; 

 the lateral rootlets were not robust, as the plants depended 

 on depth of root rather than on spread. The poor rainfall 

 (see table) of the district and the intense heat, combined 



RAINFALL FOR 





1914 



1915 



1 



1916 



1917 



1918 



1919 



To 



Aug. 



31,1920 



Average 



Hughes 



— 



— 





— 



— 



612 





— 



Ooldea 



— 



— 





— 



7-35 



6-75 



4 29 



7-05*(2) 



Immarna 



— 



— 





— 



— 



6-65 



5-14 



— 



Barton 



— 



— 





— 



7-63 



6-44 



4-35 



7-03*(2) 



Tarcoola 



5 -281 



3-76 



7-92 



9-20 



7-49 



7.35 



5-87 



7 33*(17) 



Kingoonya 



— 



— 



8-00 



8-65 



5-76 



a -82 



6-87 



7-05*(4) 



Eucla ... 



9-00 



7-88 



10-97 



12-77 



19 -5 1 



10-70 5-18 



j 



10-0e5*(44) 



Port Augusta ... 



6-44 



8-80 



11.26 



13-67 



7-58 



9 67 7-76 



9-43*(60) 



* { ) Number of years for average 

 t These totals are shown in inches 



with an extreme evapcfration, tends to the production of an 

 elaborate root system. This is specially necessary in the 

 plants growing along the tops of the sandhills. Growing 

 chiefly on the flats, between the sandhills, were : Zygophi/llum 

 fruticulosum. Euphorbia Drummondii^ varieties of Sida 



