This shrub is flowering well beside Perrin Creek in the Seven Hills Bushland. The Black Thorn (Bursaria spinosa) not only has a beautiful floral display this time of year (summer) it also comes armed with long spikes to deter predators (and provide protective habitat). It also plays host to a mutually beneficial relationship between two insects, the Bright Copper butterfly (Paralucia aurifera) and an ant species Anonychomyrma nitdiceps. It starts with the butterfly laying its eggs under the leaves of the Black Thorn. The hatched caterpillars feed on the leaves before pupating in the soil below. The ants help the pupa by digging protective tunnels for them to hide. In return, it is thought that the ants receive nutritious sections from the caterpillars.