| 1. | Lemma of lowest floret with a short apical hook-like bristle |
*C. pilosa (NT) |
| Lemma of lowest floret awned | 2 | |
| 2. | Spikelet blunt at apex | 3 |
| Spikelet narrowed to pointed at apex | 8 | |
| 3. | Lowest floret lemma hairy on lower margin |
4 |
| Lowest floret lemma glabrous on margin | 6 | |
| 4. | Awns much longer than spikelets | *C. virgata (NSW VIC NT SA WA QLD) |
| Awns shorter to slightly longer than spikelets |
5 | |
| 5. | Inflorescence spikes to 6cm long; marginal hairs of lemma projecting prominently |
*C. ciliata (QLD) |
| Inflorescence spikes more than 8cm long; marginal hairs of lemma adpressed to margins |
*C. gayana (NSW VIC NT SA WA QLD) |
|
| 6. | Spikelet 3-awned | *C. inflata (NT SA WA QLD) C. barbata auct. |
| Spikelet 2-awned | 7 | |
| 7. | Lemma of lowest floret overlapping second floret, hiding it from view |
C. ventricosa (NSW VIC SA QLD) |
| Lemma of lowest floret not overlapping second floret, which is clearly visible |
C. truncata (NSW VIC NT SA WA QLD) | |
| 8. | Lemma 1-awned | 9 |
| Lemma 3-awned | 11 | |
| 9. | Tufted annual; spikes 4-7cm long | C. pectinata (NSW NT SA WA QLD) |
| Stoloniferous or decumbent perennial; spikes 8-20cm long |
10 | |
| 10. | Spikelet-bearing axes 3-6, rigid | C. divaricata var. cynodontoides (QLD) C. cynodontoides |
| Spikelet bearing axes 5-8, flaccid | C. divaricata var. divaricata (NSW NT QLD) | |
| 11. | Lemma awns subequal, the central slightly longer |
C. obata (NT WA QLD) |
| Lemma awns very unequal | C. pumilio (NT WA QLD) C. ruderalis |
Taxonomic name: