Vachellia cornigera (Bullhorn Acacia)

Native from Mexico to Central America, this shrub or small tree has paired, swollen spines resembling bull horns and finely divided leaves. Ants live inside the hollow spines and defend the plant, receiving nectar and nutrient-rich food bodies from its leaves. Pale yellow flowers form dense cylindrical spikes, followed by reddish to maroon pods that remain closed when ripe. It grows in lowland wet to seasonally dry habitats and has naturalized in the West Indies and southern Florida, United States. Photographed on the mountain above Piojo, Colombia.