| 1. | Utricle (female inflorescence) extended into leaf base; rhizomatous perennial | C. gasteenii (QLD) |
| Utricle (female inflorescence) not extended into leaf base; tufted annual | 2 |
|
| 2. | Male spikelets numerous in a dense raceme | *C. lingulata (QLD) |
| Male spikelets few in a lax raceme | *C. lacryma-jobi (NSW WA QLD) |