Black Wattle (Acacia mearnsii)










Hawaii Pacific Weed Risk Assessment: 15 High Risk

Regulatory Status: Hawaii Noxious Weed List

Prevention and Control Category: N/A


  • Fast growing tree. All parts finely hairy. Hairs of new growth is golden in color. Leaves are dark olive-green and also finely hairy, bipinnate; leaflets short (1.5 – 4mm) and crowded. Raised glands occur at and between the junctions of pinnae pairs. Flowers form in large globular clusters and are pale yellow or cream colored. Fruits are dark brown pods. 


  • It threatens native habitats by competing with indigenous vegetation, replacing grass communities, and reducing native biodiversity

  • Increases water loss from riparian zones due to high transpiration rates

  • Long lived seeds readily germinate after fire


  • Distribution in Hawaii is currently unknown

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