For 10 points, name this scrubby region that covers over half of both Bolivia and Paraguay.
The soap fragrance Oil of Guaiac comes from a species of Bulnesia unique to this region, and Unitán, a tannin producer, uses the quebracho trees found only here. Trinidad, Resistencia, and Tucumán are among the few significant cities in this homeland of the Exnet and Ayoreo, whose name means "hunting land" in Quechua. Rumors of oil led to a war in the 1930s in this region that lies south of the Pantanal and north of the Pampas. For 10 points, name this scrubby region that covers over half of both Bolivia and Paraguay.
The soap fragrance Oil of Guaiac comes from a species of Bulnesia unique to this region, and Unitán, a tannin producer, uses the quebracho trees found only here.
Gran {Chaco}