230 Linnean Society. [May 3, 



far south as the Plata, but does not cross the river ; and Mr. Bun- 

 bury is aware of only nine species from the southern extremity of 

 Brasil. 



Leguminosce by no means form so important a part of the vegeta- 

 tion of the Argentine region as in tropical Brazil, the South of 

 Europe, or Australia. Those of the region in question belong, with 

 few exceptions, to genera widely diffused, such as Crotularia, Lupi' 

 nus, Tephrosia, Indigofera, Desmodium, ^schynomene, Lathyrus, Cli- 

 toria, Cassia, Mimosa, Inga, and Acacia. The observation already 

 made as to the small number of peculiar forms in the Argentine 

 Flora when compared with that of the Cape, and with corresponding 

 latitudes in Australia, is particidarly exemplified in this important 

 family. It will be observed also, that all the genera above enume- 

 rated (except two, or perhaps three) have their head-quarters within 

 the tropics, and only straggle, as it were, into cooler latitudes ; and 

 one is almost tempted to say, that the vegetation of this region is a 

 mere modification, a reduced or dwindled form of the Brasilian, in- 

 stead of a separate and strongly marked Flora, like that of the Cape. 

 At the Cape Lotece predominate remarkably ; in the region of the 

 Plata Hedysarea and Phaseolece are at least equally numerous. Ccesal- 

 pinecE and Mimosecs are more numerous on the banks of the Plata than 

 in the same latitudes in South Africa, where south of the Orange River 

 Dr. Burchell knows of only two species oi Acacia, although these are 

 so abundant (one of them in particular) as to give a distinctive cha- 

 racter to the scenery. Mr. Fox's collections from Buenos Ayres and 

 Uruguay include five species of Mimosa, one of Desmanthus, two of 

 CaUiandra, and five of Acacia ; yet none of these are so abundant as 

 to form characteristic features of the country. There are several spe- 

 cies of Cassia natives of Buenos Ayres ; but the magnificent Poin- 

 ciana Gilliesii, although well established on the banks of the Plata, is 

 said not to be indigenous. Daubentonia punicea was found by Mr. 

 Fox to grow wild sparingly on the bank of the Plata below Buenos 

 Ayres, and in great abundance and beauty on the banks of the Uru- 

 guay near its mouth ; and Mr-. Bunbury thinks it quite possible that 

 Cavanilles, who only saw it in a Botanic Garden, may have been 

 misinformed as to its native country, which he states to be " New 

 Spain," although it is also possible that it may be common to both. 

 Several European species are naturalized at Buenos Ayres, such as 

 Medicago sativa, M. denticulata, Trifolium repens, and Melilotus par- 

 viflora. Indigofera Anil, apparently general throughout the hotter 

 parts of America, was observed by Mr. Fox to be common all through 

 South Brasil and the Banda Oriental, but not to occur south of the 



