Ziziphus mauritiana
Native to parts of Africa and southern Asia, this thorny shrub or small tree can reach about 26 feet tall. Its zigzag branches carry glossy leaves with pale undersides. Small greenish-white flowers produce edible fruits with a hard stone. It favors open, dry habitats and usually sheds its leaves during the dry season, regrowing when rains return. Animals spread its seeds. Naturalized in Colombia, it is invasive in Queensland, Australia, where dense thickets displace native vegetation and hinder the movement of livestock and wildlife. Photographed in Colombia.