470 Linnaan Society. 



five belong to tins section. One of these (JS. aquaticum P) is a con- 

 spicuous ornament of the marsh-ditches near Buenos Ayres ; and 

 another (seemingly E. Pristis) extends from the tropical regions of 

 Brasil as far as 30° S. This part of South America seems to be 

 destitute of those curious Mulinece, which are so characteristic of 

 Fuegia, the Chilian Andes and the Falkland Islands ; but several 

 European Umbelliferee have become naturalized, and among them 

 the common Fennel, which covers the banks of earth between the 

 cultivated fields in immense profusion, and forms a distinctive feature 

 in the scenery. Mr. Darwin observed the range of the Fennel in 

 the south to be limited by the Rio Salado, rather less than 100 

 miles south of Buenos Ayres. 



MalpighiacecB. — Only two species are found on the south side of 

 the Plata, viz. Stigmaphyllum littorale and Heteropterys glabra. In 

 Rio Grande, Mr. Fox collected nine Malpighiaceee, of which one is 

 a Gulphmia, and the rest belong to Banisieria, Sligmaphyllum and 

 Heteropterys. 



Tropoioleee. — The only plant of this family (the head-quarters of 

 which are evidently on the western side of the continent) found on 

 the eastern side of temperate South America is TropcBolum penta- 

 phyllum, abundant in the hedges about Buenos Ayres. 



(Enotherea, Endl. — Some species of Jussicea are plentiful on the 

 marshy shores of the Plata, and Mr. Bunbury possesses three species 

 of CEnothera from Buenos Ayres ; but Epilobium. and Fuchsia are 

 wanting in the Argentine region, 



Melasiomacece. — One species only, as before mentioned, extends as 

 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. 



Leguminosa 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. 'I'liose of the region in question belong, with 

 few exceptions, to genera widely diffused, such as Crotalaria, Lupi- 

 nus, Tephrosia, Indigofera, Desmodium, ^schynomene, Lalhyrns, 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 particularly 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 Hedysareae and Phaseolece are at least equally numerous. Ccesal- 

 pinetE and Minwsece 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- 



