llanos (yäˈnōs) [key], Spanish American term for prairies, specifically those of the Orinoco River basin of N South America, in Venezuela and E Colombia. The llanos of the Orinoco are a vast, hot region of rolling savanna broken by low-lying mesas, scrub forest, and scattered palms. Elevation above sea level never reaches more than a few hundred feet. During the dry season (November to April) the land is sear, the grass brown, brittle, and inedible; during the rainy season much of the area is inundated. The region is subject to insect plagues. The sparsely populated llanos support a pastoral economy; cattle raising is dominant. With flood control and water storage projects in the region, sections of the llanos have been turned into fertile agricultural land. Oil has been found there. Ciudad Bolívar and San Fernando de Apure are the chief cities of the region. The llanero, an expert horseman comparable to the gaucho of the Argentine pampas, is of mixed Spanish, indigenous, and black African stock. The llanero has played an important role in Venezuelan history as an ardent henchman of successive revolutionary caudillos, notably José Antonio Páez.