524 
APPENDIX. 
[B. 
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 Orchideag, 
Piper, Dracontium and Calladium (genera of Aroideae), 
Commelina and Aneilema, Calamus and Seaforthia, Hellenia 
a solitary Australian genus of Scitamineae, some genera of 
Rubiacese, particularly Psychotria and Coffea, certain genera 
of Asphodeleae, as Cordyline, and a genus allied to it, whose 
fructification is at length obtained, a solitary plant of Me- 
lastomeee, 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 Epacrideae observed during the late 
voyages), the families Bignoniacese, Jasminese, the genus 
Erythrina, and of Coniferm, Araucaria 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 parching 
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 plants of the South and 
South-west Coasts, and particularly that none other of their 
genera of Proteacese, (than those already mentioned,} found, 
