Small, mostly broad tree 5-10 m tall with angled and finely hairy branchlets, the bark often exuding gum. Leaves bipinnate, downy, the axis with a gland at the junction of each primary division and other glands scattered between these. Leaflets 1.5-4 mm long and less than 1mm wide. Flower clusters prolific, terminal. Flower heads globular, pale yellow, fragrant; spring. Fruit pods 5-10 cm long, 5-8 mm wide, covered with fine white hairs.
Other species with flowers in racemes include: A. deanei (R.T. Baker) Welch, Coombs & McGlynn from Qld, NSW and Vic, which differs from A. mearnsii in having 2-8 primary leaf divisions, each with 10-30 leaflets to 1 cm long; A. irrorata Spreng., Green Wattle, from Qld and NSW which has branchlets with rough ribbing, glands across the upper primary divisions only (not between), and leaflets that are less than 5 mm long and the same shade of green on both sides; A. leucoclada Tindale from Qld and NSW which has waxy-blue branchlets with silvery or whitish tips, leaf stalks with 1 or 0 glands, leaves with more than 6 primary divisions, 18-40 pairs of leaflets, and fruits with prominent margins; A. pruinosa Benth., Frosty Wattle, from Qld and NSW, which is a tree to 10 m tall with waxy new growth, leaves of 3-5 primary divisions with a large slit-like gland between the lowest pair, leaflets to 1.5 cm long; and flowers 45-60 per head; and A. schinoides Benth. from NSW, which has a characteristic large round gland between the base of the first primary leaf division and the base of the leaf stalk, flowers pale yellow, 27-40 per head in long clusters.
Grown for its rapid growth rate; prefers moist soils.
SA, Tas, Vic, NSW, Qld.
Leaflets 30-70 pairs (not less than 30 as in A. dealbata or 12-20 as in A. baileyana)
Source: (2002). Mimosaceae. In: . Horticultural Flora of South-eastern Australia. Volume 3. Flowering plants. Dicotyledons. Part 2. The identification of garden and cultivated plants. University of New South Wales Press.