Description:

• Trees or shrubs, sometimes scandent or climbing, rarely undershrubs, unarmed or thorny or spiny
• Leaves bipinnate, with leaflets often small and many-jugate, or with petiole expanded in some Australian species into phyllodes, with glands often present on petiole; stipules spinescent, inconspicuous, or occasionally membranous
• Flowers in heads, in axillary or terminal spikes, solitary, fascicled, or on panicled peduncles, often sessile, bisexual or sometimes unisexual with few bisexual
• Calyx usually present, campanulate, usually (3)4- or 5-toothed or lobed; sepals rarely free
• Petals (3)4 or 5, usually united, rarely free or 0
• Stamens many, exserted, free or united at base
• Ovary sessile or stalked, 2-many-ovuled; style filiform, with small, terminal stigma
• Pod 2-valved or indehiscent, variable in shape
• Seeds compressed, with filiform to fleshy funicle
• x = 13 (aneuploids, high polyploidy)

Nomenclature:

• Acacia Mill.
  • Miller: [25] (1754)
  • Harvey: 279 (1862)
  • Brenan: 49 (1959)
  • Brenan: 53: (1970)
  • Ross: 24 (1975)
  • Ross: 22 (1979)

Distribution & Notes:

• Global: Species ± 900, mostly tropical or subtropical, mainly in Africa and Australia
• Southern Africa: Species 46, indigenous, widespread
  • Several Australian species have become naturalised