| 1. | Awned lemmas bilobed | 2 |
| Awned lemmas entire | 4 | |
| 2. | Rachis internodes c. 7 mm long | B. bunyensis (QLD) |
| Rachis internodes c. 5 mm long | 3 | |
| 3. | Raceme hairs densely silky, up to 8 mm long | B. erianthoides (NSW QLD) |
| Raceme hairs slightly silky, up to 5 mm long | B. biloba (NSW QLD) | |
| 4. | Pedicelled spikelets ±similar to sessile spikelets | 5 |
| Pedicelled spikelets very different to sessile spikelets | 9 | |
| 5. | Racemes not subdigitate; on a main axis 4-14 cm long | 6 |
| Racemes subdigitate; on a main axis less than 4 cm long | 7 | |
| 6. | Sessile spikelets c. 4 mm long, not or vary rarely pitted | B. bladhii subsp. bladhii (NSW NT SA WA QLD) B. intermedia |
| Sessile spikelets c. 3.5 mm long, sessile or pedicelled spikelet always pitted | *B. bladhii subsp. glabra (NSW QLD) B. glabra |
|
| 7. | Leaf blades with a distinctive white marginal band; spikelets not or very rarely pitted | B. ewartiana (NSW NT SA WA QLD) |
| Leaf blades without distinctive white marginal band; spikelets always pitted | 8 | |
| 8. | Sessile spikelets 4-5 mm long, glabrous to slightly hairy in basal part | *B. insculpta (QLD) |
| Sessile spikelets 3.5-4 mm long with white hairs in basal part | *B. pertusa (QLD) | |
| 9. | Sessile spikelets 5-7mm long; stamens 3 | B. macra (NSW VIC TAS SA QLD) B. ambigua |
| Sessile spikelets 4.75-5.25 mm long; stamens 1 | 10 | |
| 10. | Slender plants to 1 m tall | B. decipiens var. decipiens (NSW QLD) |
| Robust plants 1-2 m tall | B. decipiens var. cloncurrensis (NT QLD) |
Key to Bothriochloa derived from Blake 1944b; Simon 1982b, 1989b
Taxonomic name: