| 1. | Lower glume 5-nerved in lower half on back | 2 |
| Lower glume 3-nerved in lower half on back | 4 | |
| 2. | Spikelets 5.5-6.5 mm long | N. minor (WA) |
| Spikelets 8-13 mm long | 3 | |
| 3. | Upper floret 8-8.5 mm long; leaf-sheaths densely woolly outside | N. lanigera (SA WA) |
| Upper floret 5-6.4 mm long; leaf-sheaths not woolly outside | N. alopecuroidea (VIC SA WA) | |
| 4. | Spikelets 7-11 mm long; culm-nodes glabrous | N. tenuifolia (NT QLD) |
| Spikelets 5-7 mm long; culm-nodes hairy | 5 | |
| 5. | Inflorescence tightly clustered; lower glume drawn out to a fine point | N. queenslandica (QLD) |
| Inflorescence loosely clustered; lower glume blunt to acute | N. munroi (NSW NT SA WA QLD) |