| 1. | Inflorescence dense and spike-like | *A. praecox (NSW VIC TAS WA) |
| Inflorescence open and spreading | 2 | |
| 2. | Pedicels 3-8 times spikelet length | 3 |
| Pedicels up to 3 times spikelet length | 4 | |
| 3. | Spikelets 2.5-3.5 mm long | *A. provincialis (NSW) |
| Spikelets 1.5-2.5 mm long | *A. elegantissima (NSW VIC TAS SA WA) A. elegans |
|
| 4. | Spikelets 2-2.5 mm long; leaves scattered along culm |
*A. cupaniana (NSW VIC SA WA QLD) |
| Spikelets 2.3-3.5 mm long; leaves mostly basal |
*A. caryophyllea (NSW VIC TAS SA WA QLD) |
Key to Aira derived from Tutin 1980; Wheeler, Jacobs & Norton 1982; Weiller, Kodela & Thompson 2009.
Taxonomic name: