| 1. | Inflorescence of 2 racemes at end of a culm, sometimes with a third one below | 2 |
| Inflorescence of 1-many racemes along a common elongated axis | 7 | |
| 2. | Spikelets c. 1.5 mm long | *P. conjugatum (NSW NT WA QLD) |
| Spikelets 2.5-4.5 mm long | 3 | |
| 3. | Upper glume finely pubescent |
*P. distichum (NSW VIC TAS SA WA QLD) P. paspalodes |
| Upper glume glabrous | 4 | |
| 4. | Rhizomatous; spikelet width ±2/3 length | *P. notatum (NSW WA QLD) |
| Stoloniferous or tufted; spikelet width ±1/2 length | 5 | |
| 5. | Plants tufted | P. multinodum (QLD) |
| Plants stoloniferous | 6 | |
| 6. | Racemes to 7.5cm long; spikelets 3-3.5mm long |
*P. vaginatum (NSW VIC NT SA WA QLD) P. distichum auct. |
| Racemes to 11cm long; spikelets 4-4.5 mm long | P. batianoffii (QLD) | |
| 7. | Spikelets borne singly in 2 rows along raceme | 8 |
| Spikelets borne in pairs in 4 regular or irregular rows along raceme | 11 | |
| 8. | Plants usually less than 1 m tall |
P. scrobiculatum (NSW NT WA QLD) P. commersonii, P. orbiculare |
| Robust plant 1-2 m tall | 9 | |
| 9. | Spikelets 1.7-2.6 mm long; inflorescence with 1 raceme | *P. ciliatifolium (NSW) |
|
Spikelets more than 3 mm long; inflorescence with at least 2 racemes |
10 | |
| 10. | Spikelets ± 3.5mm long, glabrous; plants with 2-6 racemes | P. multinodum (QLD) |
| Spikelets ± 4mm long, slightly hairy; plants with at least 13 racemes | *P. fasiculatum (WA) | |
| 11. | Spikelets less than 1.5 mm long | *P. paniculatum (NSW QLD) |
| Spikelets 2-4 mm long | 12 | |
| 12. | Fertile lemma brown, distinctly convex | 13 |
| Fertile lemma white to straw-coloured, gently convex | 17 | |
| 13. | Spikelets 2-2.4 mm long | *P. mandiocanum (NSW QLD) |
| Spikelets 2.5-3 mm long | 14 | |
|
14.
15. |
Plants rhizomatous | 15 |
| Plants tufted, not rhizomatous | 16 | |
| Spikelets loosely and sparsely hairy, without hairs concentrated along the margins; leaves to 3.5 mm wide | *P. nicorae (NSW) | |
| Spikelets with white hairs to 0.5 mm long, sometimes oncentrated along the margins; leaves 1.2-2 cm wide | *P. regnelii (NSW) | |
| 16. | Spikelets glabrous; fruit dark brown and shining | *P. plicatulum (NT WA QLD) |
| Spikelets pubescent; fruit light brown, not shining | *P. virgatum (QLD) | |
| 17. | Spikelets fringed with long silky hairs | 18 |
| Spikelets without long silky hairs | 19 | |
| 18. | Spikelets 3-4 mm long | *P. dilatatum (NSW VIC TAS SA WA QLD) |
| Spikelets 2-3 mm long | *P. urvillei (NSW VIC TAS WA QLD) | |
| 19. | Rachis 2-3 mm wide | P. longifolium (NSW NT QLD) |
| Rachis less than 1 mm wide | 20 | |
| 20. | Spikelets 2-2.6 mm long | *P. quadrifarium (NSW VIC QLD) |
| Spikelets 3-4 mm long |
*P. exaltatum (QLD) P. arechavaletae |
Taxonomic name: