| 1. | Palea absent or minute, rarely up to 1/3 lemma length |
2 |
| Palea present, from 1/2 as long as lemma |
14 | |
| 2. | Lemma awned | 3 |
| Lemma awnless | 5 | |
| 3. | Inflorescence with spreading branches, naked at base |
Agrostis venusta (NSW VIC TAS) |
| Inflorescence ± contracted, bearing spikelets from near base of branches |
4 | |
| 4. | Spikelet 3-3.5mm long with awn arising near tip of lemma |
A. muelleriana (NSW VIC TAS) |
| Spikelet c. 2mm long with awn arising back of lemma |
A. boormanii (NSW) | |
| 5. | Inflorescence contracted | 6 |
| Inflorescence open | 7 | |
| 6. | Perennial; culms to 90cm high; sheaths greenish; inflorescence 10-35cm long; spikelets 1.8-2.2mm long |
A. bettyae (NSW QLD) |
| Annual; culms to 25cm high; sheaths purplish; inflorescence 20-60cm long; spikelets 2.2-3.5mm long |
A. muelleriana (NSW VIC TAS) | |
| 7. | Inflorescence to 12cm long | 8 |
| Inflorescence 12-35cm long | 12 | |
| 8. | Leaf blades 0.25-1.4mm wide | 9 |
| Leaf blades 2-2.5mm wide | 11 | |
| 9. | Inflorescence branches flexuose | A. joyceae (NSW) |
| Inflorescence branches stiffly spreading or divaricate |
10 | |
| 10. | Spikelets 1.5-2mm long; leaves mostly basal |
A. parviflora (NSW VIC TAS) |
| Spikelets 2.3-3mm long; leaves scattered along culm |
A. australiensis (NSW VIC TAS) | |
| 11. | Lemmas 1.3-1.8mm long; ligule to 5mm long, laciniate |
A. thompsoniae (NSW VIC TAS) |
| Lemmas 2-2.5mm long; ligule 1-3mm long, entire |
A. diemenica (TAS) | |
| 12. | Glumes unequal; leaf blades to 4cm long, 1mm wide |
A. sp. E (TAS) |
| Glumes subequal; leaf blades to 25cm long, 1.5-4mm wide |
13 | |
| 13. | Ligule to 8 mm long | A. sp. F (TAS) |
| Ligule 2-5 mm long | A. propinqua (NSW VIC) | |
| 14. | Ligule wider than long | 15 |
| Ligule as long as or longer than wide | 16 | |
| 15. | Lemma awnless | *A. capillaris var. capillaris (NSW VIC TAS SA WA) A. tenuis var. tenuis |
| Lemma shortly awned | *A. capillaris var. aristata (VIC) A. tenuis var. aristata |
|
| 16. | Rhizomatous; inflorescence usually open and loose |
*A. gigantea (NSW VIC TAS SA WA QLD) |
| Stoloniferous; inflorescence usually contracted and dense |
*A. stolonifera (NSW VIC TAS WA QLD) |
Taxonomic name: