1. Palea absent or minute, rarely up to 1/3 lemma length 2
Palea present, from 1/2 as long as lemma 12

2. Lemma awned 3
Lemma awnless 5

3. Inflorescence with spreading branches, naked at base A. venusta (NSW VIC TAS)
Inflorescence ± contracted, bearing spikelets from near base of branches 4

4. Spikelet 3-3.5 mm long with awn arising near tip of lemma A. muelleriana (NSW VIC TAS)
Spikelet c. 2 mm long with awn arising back of lemma A. boormanii (NSW)

5. Inflorescence contracted 6
Inflorescence open 7

6. Perennial; culms to 90 cm tall; sheaths greenish; inflorescence 10-35 cm long; spikelets 1.8-2.2 mm long A. bettyae (NSW QLD)
Annual; culms to 25 cm tall; sheaths purplish; inflorescence 20-60 cm long; spikelets 2.2-3.5 mm long A. muelleriana (NSW VIC TAS)

7. Inflorescence 12-35 cm long

A. propinqua (NSW VIC)

A. sp. E and A. sp. F in AusGrass

Inflorescence to 12 cm long 8

8. Leaf blades 0.25-1.4 mm wide 9
Leaf blades 2-2.5 mm wide 11

9. Inflorescence branches flexuose A. joyceae (NSW)
Inflorescence branches stiffly spreading or divaricate 10

10. Spikelets 1.5-2mm long; leaves mostly basal A. parviflora (NSW VIC TAS)
Spikelets 2.3-3mm long; leaves scattered along culm A. australiensis (NSW VIC TAS)

11. Lemmas 1.3-1.8mm long; ligule to 5 mm long, laciniate A. thompsoniae
Lemmas 2-2.5mm long; ligule 1-3 mm long, entire A. diemenica

12. Ligule wider than long 13
Ligule as long as or longer than wide 14

13. Lemma awnless *A. capillaris var. capillaris (NSW VIC TAS SA WA)

A. tenuis var. tenuis
Lemma shortly awned *A. capillaris var. aristata (VIC)

A. tenuis var. aristata

14. Rhizomatous; inflorescence usually open and loose *A. gigantea (NSW VIC TAS SA WA QLD)
Stoloniferous; inflorescence usually contracted and dense *A. stolonifera (NSW VIC TAS WA QLD)

Key to Agrostis derived from Vickery 1941; Morris 1990; Jacobs 2001b; Jacobs 2009

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