188 MR. BUNBURY ON THE VEGETATION OF BUENOS AYRES 
Gomphocarpus. Begonia? (There is some doubt Inga. 
Oxypetalum. about the locality of the spe- Calliandra. 
Araujia (Physianthus, Mart.). cimens of this.) Acacia. 
Philibertia. Pavonia. Parkinsonia. 
Schistogyne. Sida. Cassia. 
Lantana. Abutilon. Poinciana (perhaps introduced ?). 
Calonyction. Buttneria. Crotalaria. 
Nicotiana. Stigmaphyllon. Indigofera. 
Nierembergia. Heteropterys. Tephrosia. 
Petunia. Paullinia. Daubentonia. 
Jaborosa. Croton. Desmodium. 
Himeranthus. ; Phyllanthus. Æschynomene. 
Cestrum. Schinus. Clitoria. 
Buddlea. Chymocarpus. Camptosema, 
Scoparia? Jussiea. : Canavalia. 
Herpestes. Heimia. Galactia. 
Dicliptera. Cuphea. Vigna. 
Bignonia. Eugenia. Erythrina(E.Crista-galli, perhaps 
Argemone. Chetogastra(Arthrostemma, DeC.). introduced at Buenos Ayres). 
Passiflora. Mimosa. Rhynchosia. 
Blumenbachia. Desmanthus. Macherium. 
Such estimates are of course liable to some variation, according to the different opinions 
entertained by different botanists as to the limits of genera. In the above list I have 
taken Endlicher's ‘Genera Plantarum’ for my guide. | 
The above observations will show how materially the Argentine Flora differs, in reality, 
from that of Europe. What principally contributes to give it, at first sight, a European 
aspect, is the great number and extraordinary prevalence of naturalized European plants, 
—plants evidently introduced in the first instance by accident, and which, being of a hardy 
constitution, and possessing efficient means of propagation, have spread so rapidly as to 
cover the soil to a great extent, and actually to predominate over the native growth. No 
small proportion of the plants which a stranger will observe in his first rambles in the 
neighbourhood of Buenos Ayres are colonists from our quarter of the globe. The fallow 
fields about that city are blue with Echium violaceum; the banks of earth are covered 
with the common Fennel; the ditch-sides and waste ground are overrun with Chenopo- 
dium album, Sonchus oleraceus, and Xanthium spinosum; Trifolium repens and Medicago 
denticulata form much of the herbage near the river-side; and among the most common 
grasses are Lolium perenne and multiflorum, Hordeum murinum and H. pratense. What 
is more remarkable, these intrusive strangers are not confined to the cultivated lands or 
to ihe neighbourhood of the city, but have spread far and wide over the open plains. The 
“thistles” and “clover” which clothe the Pampas of Buenos Ayres for leagues and leagues 
together, have been described by many travellers; they are Carduus Marianus, Cynara 
Cardunculus, and Medicago denticulata, all of them European species. The two former 
ak spread themselves also over the country north of the Plata, where M. de St. Hilaire 
Mies os ee wide tracts of country. It would seem that these temperate regions 
rica are peculiarly favourable to the growth of European plants, and that 
