| 1. | Racemes distinctly hairy with white spreading hairs | 2 |
| Racemes not distinctly hairy with white spreading hairs | 3 | |
| 2 |
Leaf blades flabellate; racemes in compound spatheate inflorescences |
A. virginicus (NSW VIC QLD) |
| Leaf blades not flabellate; racemes simple, digitate, terminal | A. eucomus (NSW) | |
| 3. |
Leaf blades falsely petiolate; lower glume of sessile spikelet entire at apex |
A. gayanus (NT WA QLD) |
|
Leaf blades not falsely petiolate; lower glume of sessile spikelet bifid at apex |
A. distachyos (WA ) |
Key to Andropogon derived from Vickery 1961
Taxonomic name: