| 1. | Central awn more than 2 mm long, twisted at base | P. urvillei (NSW) Danthonia vickeryae, D. urvillei |
| Central awn shorter than 2 mm long or absent | 2 | |
| 2. | Spikelets 2-3-flowered; central awn absent or greatly reduced | P. rodwayi (NSW) Danthonia rodwayi |
| Spikelets 3-5-flowered; central awn distinct | P. paradoxa (NSW VIC) |
Key to Plinthanthesis derived from Blake 1972b
Taxonomic name: