Many species are present in New Zealand but often only represented by a single clone. Leaves usually alternate, trunks sometimes lying down and rooting at nodes.
Leaves lanceolate or elliptic to oval.
Sometimes shallowly toothed. The branchlets break easily with an audible crack when bent. Nearly all the plants are female. Crack willow forms dense stands in rivers and drains and is locally abundant. Forms dense stands totally excluding native vegetation.