Weed Habitat

  • Considered to be from tropical America, this weed invades disturbed and overgrazed areas.


  • An erect small shrub growing to around 1.5 m.
  • Stems woody, branching several times, with well-developed tap root.
  • Leaves narrow, lance shaped, tapered both ends, serrated edges.
  • Yellow flowers, usually solitary or in pairs in the leaf axils.
  • Fruit is a hard, dark brown dry capsule, splitting into 5-8 segments each with a wedge-shaped, black seed having 2 sharp points at one end.

Spiny head sida - Sida acuta - flower

Spiny head sida - Sida acuta


Currently not declared however under the Biosecurity Act 2014 you still have an obligation to prevent or minimise a biosecurity risk posed by a pest.