AND THE NEIGHBOURING DISTRICTS. 197 
Œnothereæ (Endl.).—Of the four principal genera of this family, Jussiea, Œnothera, 
Epilobium and Fuchsia, the Argentine region possesses only the first two. Some species 
of Jussiæa are plentiful on the marshy shores of the Plata, but as the genus has its head- 
quarters within the tropics, so it is richer in species at Porto Alegre than at Buenos 
Ayres. From this latter place I possess three species of Œnothera. Fuchsia, so charac- 
teristic of the west side of South America, seems, on the eastern side, to be confined to 
tropical Brazil. 
Melastomace@.—One species only (as I have already mentioned) extends as far south 
as the Rio de la Plata, but does not appear on the southern bank of that river. Even in 
Rio Grande, the plants of this order are few when compared with their abundance in 
tropical Brazil, and when compared also with the allied family of Myrtles. I am aware of 
only nine species from the southern extremity of Brazil. 
Leguminose.—The Argentine region is not particularly rich in these plants; at least, 
they by no means form so important a part of the vegetation as in tropical Brazil, in the 
south of Europe, or in Australia. The Legwminose of the region in question belong, with 
few exceptions, to genera widely diffused, such as Crotalaria, Lupinus, Tephrosia, Indigo- 
fera, Desmodium, ZEschynomene, Lathyrus, Clitoria, Cassia, Mimosa, Inga, Acacia. This 
is quite a contrast to what is observable at the Cape of Good Hope, where the number of 
peculiar or endemic genera of this order is remarkably great. The observation which I 
have already made, as to the small number of peculiar forms in the Argentine Flora, when 
. Æompared with that of the Cape, is particularly exemplified in this important family. The 
same holds good, perhaps in a still greater degree, if we compare it with the Flora of corre- 
sponding latitudes in Australia. It may be observed, also, that the greatest part of the 
Leguminose of the Plata belong to genera which are principally tropical, and which only 
straggle, as it were, into cooler latitudes; such are all but two, or perhaps three, of the 
genera mentioned above, One is almost tempted to say that the vegetation of this region 
is a mere modification, a reduced or dwindled form, of the Brazilian, instead of being a 
separate and strongly marked Flora like that of the Cape. 
Again, at the Cape, the Lotee predominate remarkably over the other papilionaceous 
tribes; in the region of the Plata, the Hedysaree and Phaseoleæ are at least equally 
numerous. Cesalpinee and Mimosee are more numerous on the banks of the Plata than 
in the same latitudes in South Africa. In that country, south of the Orange River, I 
know of only two species of Acacia, although these are so abundant (one of them espe- 
cially) as to give a distinctive character to the scenery; nor, as far as I am EOS 
there any other Mimosee south of the same river, although, to the north of it and at 
Natal, (about the latitude of the southern extremity of Brazil,) they become numerous. 
Mr. Fox’s collections from Buenos Ayres and Uruguay (between 33° and 35° 8. lat.) 
include five species of Mimosa, one of Desmanthus, two of Calliandra, and five of Acacia ; 
yet none of these are so abundant as to form characteristic features of the country, like 
the Acacia horrida and Caffra in the eastern part of the Cape colony. The Casalpinee 
of these latitudes are principally Cassie, of which there are several species at Buenos 
Ayres. The magnificent Poinciana Gilliesii is said not to be indigenous there, though 
now well established on the banks of the Plata. 
