Acacia farnesiana Alias: duck soap tree, thorn ball flower, message tree, etc.; shrub or small tree, bark rough, brown, multi-branched, branchlets often curved in a zigzag shape, with small lenticels. Stipules needle-like, shorter on branchlets. Two-pinnate compound leaves, rachis-shaped, covered with off-white pilose, 4-8 pairs of pinnae. Flowers yellow, fragrant; ovary cylindrical, puberulent. Pods swollen, nearly cylindrical, brown, glabrous, straight or curved; seeds many, brown, ovate, flowering period March-June; fruit period July-November.

Shrubs or small trees, 2-4 meters high; bark of Acacia farnesiana rough, brown, much branched, branchlets often zigzag curved, with small lenticels. Stipules needle-like, spines 1-2 cm long, shorter on branchlets.
Bipinnate compound leaves are 2-7 cm long, rachis-shaped, gray-white pilose, with glands; pinnae 4-8 pairs, 1.5-3.5 cm long; leaflets usually 10-20 pairs, linear oblong Shaped, 2-6 mm long, 1-1.5 mm wide, glabrous.
Acacia farnesiana flower heads 1 or 2-3 in clusters in leaf axils, 1-1.5 cm in diameter; the total pedicel is hairy, 1-3 cm long, bracts are located at or near the top of the general pedicel; flowers are yellow, fragrant; calyx 1.5 mm long, 5-toothed; petals commissure tubular, about 2.5 mm long, 5-toothed; stamens about twice as long as corolla; ovary cylindrical, puberulent.
Pods swollen, nearly cylindrical, 3-7 cm long, 8-15 mm wide. Brown, glabrous, straight or curved; Acacia farnesiana seeds many, brown, ovate, about 6 mm long. The flowering period is March-June; the fruiting period is July-November.