| 1. | Cleistogamous inflorescence of one type; cleistogamous and chasmogamous spikelets similar |
D. rigida |
| Cleistogamous inflorescence of two types; cleistogamous and chasmogamous spikelets dissimilar |
2 | |
| 2. | Chasmogamous spikelets more than 5 mm long; sessile cleistogamous spikelsts more than 8 mm long |
D. sp. (Charters Towers, Thompson CHA555 & Thomas) |
| Chasmogamous spikelets less than 5 mm long; sessile cleistogamous spikelsts less than 6 mm long | D. sp. (Miles, Thompson 888) | |
| D. sp. (Mt. Cooper, R.J.Cumming 18623) |