The Compositae of Baenos Aires. Revision of the Compositae of the Province of Buenos Aires, the federal capital and the Island of Martin Garcia.
The region is an extensive plain having two mountain ranges. Seven different types of vegetation are distinguished. (1) Loess plains of steppe or prairie-steppe in which grasses of the genera Siipa, Briza, Melica, Poa etc. predominate. (2) Sandy plains of the west, formed of grass steppe with Sporobolus rigens and Panicum unvilfeanum dominant. (3) Hill vegetation; numerous shrubs, abundance of. grasses, and endemic species: of Festuca and Stipa. (4) Alluvial lands of the Paraná delta and the western shore of the La Plata, where dense growths of Gramineae and Cyperaceae are included among the plant associations. (5) Narrow wooded belt in the north-east. (6) Seacoast dunes, having a few herbaceous species mainly comprising grasses such as Panicum racemosum, P. urvilleanum, Spartina ciliata, and Sporobolus rigens. (7) Salt, sandy lands of the south of the province.-From author's summary.