194 MR. BUNBURY ON THE VEGETATION OF BUENOS AYRES 



tine region, the local conditions of which appear favourable to this family. I will there- 

 fore not attempt to estimate the proportional number of Grasses to other orders. I will 

 merely observe, that, besides some European grasses evidently naturalized in that region*, 

 there are some apparently indigenous species which have a very wide range. Such are 

 Cynodoti dactylon, which seems to be a native of all the warmer parts of the world, in 

 both hemispheres ; Setaria glauca, equally cosmopolite ; Setaria italica, of which I have 

 specimens from Louisiana as well as from the Uruguay, and which is stated to be a native 

 of Europe, India and New Holland ; Eleusvne indica, which appears, from the localities 

 given by Kunth, to have a vast range in the tropical and subtropical zones ; Polypogon 

 monspeliensis, which I have myself seen at the Cape of Good Hope and at Buenos Ayres, 

 as well as in the south of Europe ; Stenotaphrum gldbrum, common to the Cape, Lou- 

 isiana, tropical Brazil, and the northern shore of the Plata. The beautiful grass Eustachys 

 petrcea may be added, if the Cape plant be really the same with the South Americam 

 which does not seem quite certain. 



Eriocaulonece. — Of this family, so very numerous in tropical South America, and espe- 

 cially in the interior mountainous districts of Brazil, I find only one species in Mr. Fox's 

 collections from the extreme southern part of that country. This is Eriocaulon (Pcepa- 

 lanthus) caulescens, of which there are specimens from Porto Alegre, S. lat. 30° ; I met 

 with it in Minas Geraes, not far from S. Joao d'El Bey ; and I have seen a specimen from 

 Guiana in Sir J. E. Smith's herbarium. 



Alismacea. — A fine species of Sagittaria is plentiful in the marshy pools near the river- 

 side at Buenos Ayres ; it is, I suppose, S. Montevidemis of Chamissof, though it differs 

 from his specific character in having the back of the leaf quite smooth. It certainly comes 

 very near to S. sagittifolia, though much larger both in the leaves and flowers. The 

 downy filaments of the stamens, and yellow anthers, seem, as far as I can judge, to furnish 

 the most certain characters ; for the leaves of our English Arrow-head are so very variable, 

 that it is hardly safe to rely upon the distinctions afforded by their more suddenly and 

 sharply acuminated lobes in the Buenos- Ayrean plant. 



Composites. — The celebrated botanist, Schouw, has characterized the countries near the 

 Plata as the " Kingdom of Arborescent Composites'" a title scarcely applicable, for these 

 plants, like most others of the region in question, have for the most part a herbaceous 

 character. 



Here, as in South America generally, the Composites appear to be the most numerous 

 family of plants ; but I am not able to state their proportional numbers with precision. 

 Almost all those of the Argentine region belong to the Cotymbifercs of Jussieu ; the Cicho- 

 racecs and Cynarecs hardly occur at all, except in a naturalized state. The Labiatiflorce, 

 so characteristic of the western side of South America and of the Andes, are few and 

 inconspicuous in this region. It is curious, that the genus Mutisia, which ranges all up 

 the west side of the continent from southern Chile into New Granada, and is scattered 

 also through Brazil, as far south as Porto Alegre, does not seem to extend to the Plata. 

 I must own, however, that negative conclusions in such cases are a little uncertain, unless 

 they rest upon the concurrent testimony of many observers. 



* See before, p. 188. t Kunth, Enumeratio Plantarum, vol. iii. p. 157. 



