Prosopis flexuosa, commonly known as tortuous mesquite and a variety of Spanish vernacular names including algarrobo dulce and algarrobo negro, is a species of flowering tree in the genus Prosopis of the family Fabaceae. It is found in arid and semi-arid regions of Argentina, Bolivia and Chile, including the western Gran Chaco and the Monte Desert, where it is a conspucuous and characteristic plant of the region. Its timber is used for construction, charcoal and fuel and its fruits are eaten by humans and livestock.