Page:Narrative of a survey of the intertropical and western coasts of Australia, Volume 2.djvu/549

 others, frequent upon the East Coast, that' appear wholly wanting on the north-western shores: of these, the ex- istence of some, even in the tropical parts of New South Wales, seems governed by the primary formation of the coast, its mountainous structure, and consequent perma- nency of moisture in a greater or less degree; namely, almost all the genera of Filices, the parasitical Orchide, Piper, Dracontium and Calladium (genera of Aroidea), Commelina and Aneilema, Calamus and Seaforthia, Hellcain a solitary Australian genus of Scltaminee, some genera of Rubiacee, particularly Psychotrla and Colfen, certain genera of Asphodeleee, as Cordyline, and a genus allied to it, whose fructification is at length obtained, a solitary plant of Me- ]astomem, and an individual Nymphea. Other genera also, but little influenced by those local circumstances of situation on the East Coast, that are ex- cluded from the opposite shores, are Leucopogon (the only equinoctial genus of Epacrideee observed during the late voyages), the families Bignoniaceee, Jasmines, the genus Erythrina, and of Conifers, Arancaria of Norfolk Island. This absence of several orders of plants on. the north- western shores, existing in New South Wales, or opposite coast, as well as the consideration (at the same time) of the evident causes of such a disparity of species on the former coast, would suggest the opinion, that such plants alone of other parts of the continent are indigenous to the North-west Coast, as are capable of sustaining them- selves in a soil subjected to seasons of protracted parchin droughts. This may apply to some species upon that coast, but it cannot be reduced to a general conclusion; for, on the one hand, it is singular so few of the plant of the South and South-west Coasts, and particularly that none other of their genera of Proteace, than those already mentioned,) found

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