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 
Cynodon 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; Eleusine 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 glabrum, common to the Cape, Lou- 
isiana, tropical Brazil, and the northern shore of the Plata. The beautiful grass Hustachys 
petrea may be added, if the Cape plant be really the same with the South American, 
which does not seem quite certain. 
Eriocauloneæ.—Of this family, so very numerous in tropical South America, and espe- 
eially in the interior mountainous distriets of Brazil, I find only one species in Mr. Fox’s 
collections from the extreme southern part of that country. This is Eriocaulon (Pepa- 
^ 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 Rey; and I have seen a specimen from 
Guiana in Sir J. E. Smith’s herbarium. 
Alismacee.—A fine species of Sagittaria is plentiful in the marshy pools near the river- 
side at Buenos Ayres; it is, I suppose, S. Montevidensis of Chamissot, 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. 
Composite.—The celebrated botanist, Schouw, has characterized the countries near the 
Plata as the “ Kingdom of Arborescent Composite ;” 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 Composite 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 Oorymbifere of Jussieu ; the Cicho- 
race? and Cynareæ hardly occur at all, except in a naturalized state. The Labiatiflore, 
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. 
