Acacia adunca, commonly known as the Wallangarra wattle and the Cascade wattle, is a species of Acacia native to eastern Australia. The spreading shrub typically grows to a height of 6 metres (20 ft) with a width of 3 m (9.8 ft) and has long thin phyllodes approximately 15 centimetres (6 in) in length that tend to droop. The phyllodes are dark green and lustrous and feel oily to touch. It produces masses of golden ball flowers from late winter to early spring. The flowers are borne on simple racemes that are about 30 mm (1.2 in) long and form near the terminus of the branchlets.