Nitrogen Fixation: N-fixing Plants - Wattles
Groups of Australian plants that possess N-fixing symbionts include:
- Wattles (Acacia)
- Peas (e.g. Sturt's desert pea)
- She-oaks (Allocasuarina and Casuarina)
- Cycads (e.g. Macrozamia and Cycas)
There are over 650 Australian species of Acacia and some 900 worldwide. Australian species occur in almost all vegetation types from tall-open forest to desert shrublands. Like their relatives the peas (both are members of the order Fabales), Acacias develop root nodules, which contain N-fixing Rhizobium bacteria. Acacias regenerate well after fire and can therefore play an important role in replenishing soil nitrogen.