🆔Acacia collinsii/ Vachellia collinsii This species has large, outwardly cupped spines that are in pairs at the base of leaves, which resemble the horns of a bull and are lightly or strongly brown, sometimes ivory or yellow. This acacia is known for its symbiotic relationship with ants of the genus Pseudomyrmex. The ants act as a defense mechanism for the tree, protecting it against insects and other harmful animals or against parasitic plants. The ants live in the hollow spines of the plant …