Callistachys

thumb|Habit Callistachys lanceolata, commonly known as the wonnich, native willow, or greenbush is the sole species in the genus Callistachys. It is a species of erect shrub or small tree that is native to the south-west of Western Australia and is naturalised in some other Australian states.

==Description== Callistachys lanceolata is an erect evergreen tree or shrub that typically grows to a height of and has silky-hairy young stems. The plant has conspicuous and attractive inflorescence composed of racemes with yellow flowers. The plant flowers from September to January. The leaves of the plant are leathery and are arranged in whorls, most typically with three leaves per whorl. The leaves are generally regular in shape between to in length and to in width and have pointed tips.