1. Mature spikes mostly with 4 or more joints 2
Mature spikes with 1-3 joints 5

2. Spikes more than 2 mm thick 3
Spikes less than 2 mm thick 4

3. Spikes not constricted at nodes T. major (NT WA QLD)
Spikes constricted at nodes T. monilifera (NT QLD)

4. Spikes of one type only T. pubescens (NT WA QLD)

T. constricta
Spikes of two different types T. x heteromorpha (QLD)

T. pubescens x T. major

5. Spikes constricted at the nodes, usually 3 jointed T. sp . (Morehead R., Clarkson 8086) (QLD)
Spikes not constricted at the nodes, usually less than 3 jointed 6

6. Spikes 11-20 mm long, 2-3 (rarely 1) jointed T. striata (NT)
Spikes 3-9 mm long, 1 (rarely 2) jointed 7

7. Culm with 6-9 nodes; lower glume smooth or slightly rugulose 8
Culm with 10-15 nodes; lower glume not smooth 9

8. Joints 2.5-3 mm long; lower glume concave inside view T. rariflora (QLD)
Joints 3-6 mm long; lower glume ±straight T. major (NT WA QLD)

9. Lower glume distinctly rugulose T. brassii (NT QLD)
Lower glume longitudinally ribbed T. rubra (NT)

Key to Thaumastochloa derived from de Koning, Sosef and Veldkamp
1983; Simon 1989b

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith