The key works by selecting one of the two choices given for each pair of descriptions, which lead to either another pair of descriptions or the identification of your species.
| 1. | Florets with one glume | Hainardia cylindrica (Common Barb-grass) |
| 1. | Florets with two glumes | 2 |
| 2. | Flowering spikes strongly curved; leaf sheaths inflated | Parapholis incurva (Coast Barb-grass) |
| 2. | Flowering spikes erect or slightly curved; leaf sheaths not inflated | Parapholis strigosa (Slender Barb-grass) |