| 1. | Lower glume of sessile spikelet with a deep median groove; leaf blade cordate at base |
*C. martinii (QLD) |
| Lower glume of sessile spikelet flat or concave on back; leaf blade narrow or attenuate at base |
2 | |
| 2. | Inflorescence occupying 1/10-1/5 of culm length, dense | C. globosus (QLD) |
| Inflorescence occupying 1/5-2/3 of culm length, not dense | 3 | |
| 3. | Racemes distinctly hairy, with hairs 4-7 mm long | 4 |
| Racemes only slightly hairy, with hairs less than 3 mm long | 10 | |
| 4. | Longer callus hairs up to 1.3 mm long | 5 |
| Longer callus hairs 3.5-5 mm long | 7 | |
| 5. | Leaf blades up to 3 mm wide, filiform to very narrow; culms delicate and drooping |
C. dependens (NT WA) |
| Leaf blades more than 4 mm wide; culms robust and erect | 6 | |
| 6. | Plant 1.5-2.5 m tall with 7-11-noded inflorescences; lower glume of sessile spikelet not more than 4.5 mm long |
C. procerus (NT WA QLD) C. exaltatus |
| Plant usually less than 1.5 m tall with 4-8-noded inflorescences; lower glume of sessile spikelet 5.5-7 mm long |
C. ambiguus (NSW NT SA WA QLD) C. exaltatus auct. |
|
| 7. | Sessile spikelet awnless | 8 |
| Sessile spikelet awned | 9 | |
| 8. | Lower glumes of sessile spikelet nerveless, flat on back | C. gratus (QLD) |
| Lower glume of sessile spikelet 3-nerved, flat to shallowly concave | *C. citratus (QLD) | |
| 9. | Leaf sheaths to 6 mm wide, rolling back at maturity | C. bombycinus (NT WA QLD) |
| Leaf sheaths 2-3 mm wide, not rolling back at maturity | C. obtectus (NSW VIC NT SA WA QLD) | |
| 10. | Pedicelled spikelet with 2 glumes; sessile spikelet with an awn 10-12 mm long, usually not reflexed at maturity |
C. queenslandicus (QLD) |
| Pedicelled spikelet with one glume only; sessile spikelet usually awnless (if awned, awn small and imperfect, always distinctly reflexed at maturity) |
C. refractus (NSW VIC NT QLD) |
Key to Cymbopogon derived from Blake 1944b; Soenarko 1977; Simon 1989b
Taxonomic name: