Stewart K. answered 11/27/21
AP, Research Paper, and Classroom History, Gov, and Geo Tutoring
Llanos in Venezuela/Colombia (southern Venezuela and eastern Colombia)
Campos in Brazil (a few bits of northern Brazil similar to the llanos, then along the Sao Francisco river valley inland from the coastal mountains)
Pampas of Argentina, southern Brazil, Uruguay (Rio Grande do Sul state in Brazil, most of Uruguay, east-central Argentina from Cordoba and La Pampa east to the sea)
Patagonian steppe (east side of the Andes from the pampas south most of the way to Tierra del Fuego)