nOI!N EXPKniTION SriMMArtY. I()l 



gregarious in isolated foloiiics, sonietimos occupying a few square yards, or ovoii as 

 inucli as scAcral square miles." The alien plants on the other hand are widely 

 distributed and able to adapt thenisehes to extremes of soil and climate. 



The saxatile vegetation growing on the ranges in crevices on the escarpments 

 and especially on the locky sides of the deep and shaded gorges supplies tlie 

 greater number of the characteristic Larapintine species. Thus "of seventy 

 llowering plants, restrictedly rock dwellers, seven only are of exotic origin." 



A striking feature of many of the species is either their isolation or sporadic 

 distribution. The fan-palm, for example ( IJvistona Afaricr ), is limited to a single 

 colony nlong the Finke gorge and a small tributary, the Palm Creek ; Sivaiiisnm'd 

 caiicsa'7is was only seen growing in two small colonies a few yards square and 

 separated fi'om one another by nearly eighty miles, the grass tree ( Xantlwrrluxa 

 Tliotiitoni) occupies a narrow belt of country seventy miles long by thirty wide, 

 and other species in the same way occurred only in single or in very few colonies, 

 often far apart. 



In the case of certain species we liave as it were connecting links lietween the 

 Autochthonian and Euronotian floras. Hibhertia i:;Iaherriinn for example is the 

 only species of the section Hemihibbertia extending beyond Western Australia 

 and its distribution in the centre connects it with the same species in Queensland ; 

 Gastrolol'ium <^ra?idiJ/oi-7ii!i in the same way stretches across from the west to the 

 interior of Queensland and New South Wales, and the same applies to other 

 species such as Sfyphc/ia Mitclicllii a species found in (Queensland whilst the home 

 of the genus is in West Australia. 



In the Central Ereniian region the prevclance of Salsolaceous plants is a 

 striking feature, their place being taken in the Larapintine area by grasses, the 

 most important of which are species of Triorlia oi' "porcupine" grass which extends 

 also over large areas of the ti'ue desert region stretching across to West Australia. 

 Other characteristic plants of the Central Eremian area are Cnssia ercmophila 

 and Eurah'pftis niicrotJiecn which in the Larapintine district are replaced by 

 C. f}ivIlodi)ie(i and E. rostrata. 



Atriplex r/iai:^odifl!des, Snlso/a Kali, Kocliia a/>hyi/a, Bassia diaca7itha and 

 species of Acacia such as A. aneura (Mulga), A. cyperopiiylla (red Mulga) and 

 A. hflJiialopliylla (Ciddea) are common and on loamy patches such plants as 

 LepidiuDt papillosit»i, Eupliorbia Dn/nnnoiidii, and species of Ptilotus. 



Spe.iking generally we niay legard the present flora of the centre of the con- 

 tinent as consisting of two distinct elements (1) a .series of forms which are the 



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