AND THE NEIGHBOURING DISTRICTS. 193 



Mr. Brown has indicated a few points of resemblance between the botany of Australia 

 and that of the temperate parts of South America ; but these all, I think, belong to 

 Chile. On the eastern side of the continent, within the latitudes in question, I am not 

 aware of any plant that can at all remind us of the Australian Flora. It is rather 

 remarkable, that the Protea family, which occurs, though sparingly scattered, in Puegia, 

 Chile, Peru, Guiana, and tropical Brazil, seems to be entirely absent from the region of 

 which I treat. 



I shall conclude with a few remarks upon some of the families contained in the collec- 

 tions before me, and on the range of particular species. 



Filices. — At Porto Alegre and one or two other points in the extreme south of Brazil, 

 about 30° S. lat., Mr. Pox collected fifty-four species of Perns. This collection strongly 

 exemplifies the wide range of species in this family, pointed out by Sir W. Hooker and 

 by Dr. Joseph Hooker ; for nearly the whole are natives of tropical Brazil, and at least 

 one-half of the number occur likewise to the north of the Equator, — in the West Indies, 

 Caraccas, Guiana, or Mexico. Two extend even to Europe, — Asplenium marinum and 

 Osmunda regalis. The Bio Grande specimens of this Osmunda agree perfectly with the 

 ordinary British form. 



Of the fifty-four Perns, forty-nine belong to PolypodiacecB* ; two to Gleicheniacece, two 

 to Schizceacece, and one to Osmimdacece. Two are arborescent, Didymochlcena sinuosa and 

 Alsophila armata. This, I suppose, is the southernmost limit of Tree Perns on the eastern 

 side of South America. 



Buenos Ayres is remarkably poor in this family of plants. During the month that I 

 spent there, although I paid much attention to botany, I did not observe a single Pern ; 

 and in the collections made by Mr. Pox, who, I know, took particular interest in this 

 family, I find only onet Pern from the south side of the Plata. This circumstance is not 

 at all surprising, for the bare, level, shadeless, treeless plains of Buenos Ayres are pecu- 

 liarly unsuited to the Perns. And we may observe, that even where there is a warm 

 climate and a tolerably large supply of atmospheric moisture, (for both these conditions 

 exist at Buenos Ayres,) these plants do not seem to flourish unless there be shade and 

 variety of surface. In accordance with this, is the absence of Perns from the bare table- 

 land of Mexico J, and their great scarcity on the open campos of the interior of Brazil. 

 The neighbourhood of Graham's Town, in South Africa, has a much drier climate than 

 Buenos Ayres, yet the ravines and rocks there, affording shade and shelter from the wind, 

 produce many Perns. 



Gramina. — Among the Grasses collected on the banks of the Uruguay and La Plata, I 

 find the Poacece (according to the division established by Mr. Brown) to be rather more 

 numerous than the Panicece ; the former, however, including a few naturalized species. 

 The comparatively small number of Grasses in the collection doss not allow me to sup- 

 pose that it is, in this respect, at all a fair representative of the vegetation of the Argen- 



* I follow the arrangement of Mr. J. Smith, published in Hooker's Journal of Botany. 



f This is a Blechnum (or Lomarial for Mr. Fox's specimens have no fructification) which seems to agree with the 

 description of Blechnum auriculatum, Cav. 



\ See Martens and Galeotti, Fougtres de la Mexique. 

 VOL. XXI. 2 D 



