*Sida rhombifolia

Family Malvaceae

Paddy’s Lucerne

Erect perennial subshrub to 1 m high, with deep, robust taproot.

Flowers: yellow to pale orange, December - May. Insect-pollinated probably butterflies.

Fruit: Dry segmented fruit 5 – 6 mm diameter, December - May

Seed: 9 – 12 barbed segments per fruit each containing one seed. Dispersed by adhesion to clothing and animals. Germination in less than a week.

Gallery images: seed, seedling, rootstock, resprout


  • Native of tropical regions.
  • Widespread exotic weed in woodland and roadsides.
  • Common species in woodland at the Australian Botanic Garden, forming localised patches.
  • Plants in open areas killed or debilitated by frost.
  • Seedling recruitment frequent and rapid, including after fires.
  • Killed by high intensity fire will resprout after low-intesity fire.


Useful references

Parsons, W.T. & Cuthbertson, E.G. (1992, 2001) Noxious Weeds of Australia (Inkata Press; Melbourne).

Asterisk * indicates exotic species naturalised at the Australian Botanic Garden.

Ecology of Cumberland Plain Woodland

Sida rhombifolia plant

Sida rhombifolia flower

Sida rhombifolia fruit