Tropical Flora.'] 



INTRODUCTORY ESSAY. 



:.;li 



Tropical Australia. 

 Cyperaceae. 

 Euphorbiaceae. 

 Malvaceae 

 Convolvulaceae. 

 Goodeniaceas. 

 Proteacese. 



Tropical Africa. India (trap, and temp.) 



Cyperacese. 



Acanthaceaa. 



Malvaceae. 



Euphorbiaceae. 



Convolvulacea?. 



Urticeae. 



Graminese. 



Euphorbiaceae. 



Acanthaceae. 



Cyperaceae. 



Labiatae. 



West Indies. 



Cyperacese. 



Euphorbiaceae. 



Scrophularineae. 



Melastomeae. 



Convolvulacea. 



Myrtaceae. 



Mueller has given, in his ' General Report on the Botany of the North Australian Expedition/ 

 some valuable tables, showing approximately the order of succession in which temperate forms appear 

 in advancing southward in Australia, and these give us a wide idea of the immensely extended dis- 

 tribution of many endemic species. He enumerates no less than 225 Victoria colony species as 

 occurring to the north of lat. 26° S., and of these I find nearly 90 to be Tasmanian. Many of them 

 are properly tropical forms that attain the latitude of Victoria only in the hot deserts, but many are 

 essentially temperate forms. The whole are thus distributed : — 



Lat. 17° 30' S. to 20° S. 



Victoria species, 32 ; Tasmania, 10. 



20° „ 23° 



24 „ 6. 



23° „ 26° 



51 „ 21. 



2G° „ 27° 



118 „ 52. 



The diminution of vegetable forms in advancing from temperate to tropical Australia is to a 

 great extent due to the rarity or absence of Orders which, though more typical of hot latitudes in 

 other parts of the globe, abound in the temperate regions only of Australia. I have marked these 

 with an asterisk in the following list of extratropical Australian Orders that diminish rapidly or are 

 absent in the tropics of that continent : — 



Eanunculaceae. 



Rutaceae. 



Compositae. 



Casuarinese. 



*Dill«ynacese. 



Stackhousieae. 



Lobeliaceae. 



Coniferse. 



Cruciferse. 



*Rharnneae. 



Epacrideae. 



*Orchideae. 



Tremandreee. 



Rosaceae. 



Myoporineae. 



Irideae. 



*Buettneriaceae. 



*Myrtacea8. 



Labia tae. 



Haemodoraceae. 



Geraniacere. 



Crassulaceae. 



Plantagineae. 



*Liliacea?. 



Violariee. 



Cimoniaceae. 



Proteacea?. 



Juncea?. 



Droseraceae. 



Halorageae. 



*Santalaceae. 



Xerotideae. 



*Polygaleae. 



Urabelliferae. 



Daplmea?. 



*Restiacese. 



Those Orders, again, which are confined to the Tropics, are unexceptionally common Indian ones, 

 and which it is not necessary to specify. There are, however, several of the most typically Indian 

 Orders that are very scarce or absent in tropical Australia, amongst which the most remarkable are : — 



Anonaceae. 

 Menispermeae. 

 Guttiferae. 

 CYlastrineae. 



Rhatnneae. 

 Mekstomaceae. 

 Araliaceflg. 

 Vaccinieae. 



Symploceas. 

 Myrsineas. 

 Acanthaceae. 

 Cyrtandreas. 



Laurineae. 

 Cupulifero?. 

 Dioscoreae. 

 Aroidea 3 . 



The peculiar features of the extratropical Australian Flora are mainly kept up in its tropical 

 quarter, by the following plants : — 



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