| 1. | Spikelets to 7 mm wide; pedicel articulated | *E. superba (NT VIC SA QLD) |
| Spikelets less than 5 mm wide; pedicel not articulated | 2 | |
| 2. | Plants distinctly glandular on culms below nodes or on leaf margins, inflorescence branches, pedicels, glumes or lemmas | 3 |
| Plants not or sometimes faintly glandular | 12 | |
| 3. | Annuals | 4 |
| Perennials | 9 | |
| 4. | Plants glandular on inflorescence branches, pedicels, glumes or lemmas | 5 |
| Plants glandular on culms below nodes and/or leaf margins |
8 | |
| 5. | Spikelets 2-4 mm wide | *E. cilianensis (NSW VIC TAS NT SA WA QLD) |
| Spikelets less than 2 mm wide | 6 | |
| 6. | Palea keels as long as the palea and not dividing at apex; glumes keeled | *E. minor (NSW VIC NT SA WA QLD) E. pooides |
| Palea keels shorter than the palea and dividing apically into 3 small lobes; glumes rounded on back |
7 | |
| 7. | Spikelets 0.5-1mm wide; palea persistent | E. crateriformis (NT WA) |
| Spikelet 1-1.5mm wide; palea deciduous | *E. pilosa (VIC NSW NT WA QLD) | |
| 8. | Inflorescence terminal only; caryopsis smooth on surface |
*E. mexicana (NSW VIC SA WA QLD) E. neomexicana, E. virescens |
| Inflorescence terminal on culms and branches and often axillary; caryopsis reticulate on surface |
*E. barrelieri (NSW NT SA WA) | |
|
9.
10. |
Plants viscid, with prickly tubercles; culm base bulbous | E. olida (NT WA QLD) |
| Plants not viscid, without prickly tubercles; culm base fibrous | 10 | |
| Spikelets mauve to purple, 2-4 x 1-1.2 mm | *E. trichophora (NSW QLD) | |
| Spikelets yellow to olive-green | 11 | |
| 11. | Pedicels encircled by yellow bands; panicle branches not thickened |
E. leptostachya (NSW VIC QLD) |
| Pedicels without yellow bands; panicle branches distinctly thickened |
E. alveiformis (NSW VIC QLD) E. molybdea |
|
| 12. | Spikelets terete or ±biconvex | 13 |
| Spikelets ±laterally compressed | 26 | |
| 13. | Lemma with lateral nerves closer to margin than to mid-nerve |
14 |
| Lemma with lateral nerves mid-way between margin and mid-nerve or sometimes closer to latter |
17 | |
| 14. | Spikelets 2-8-flowered | 15 |
| Spikelets at least 10-flowered | 16 | |
| 15. | Spikelets to 4-flowered, 1 x 1 mm; glume apices obtuse | E. sp. A (Currawinya, M.Page AQ 717024)(QLD) |
| Spikelets 5-8-flowered, 3 x 3 mm; glume apices with reflexed mucros | E. jerichoensis (QLD) | |
| 16. | Spikelets c. 0.5 mm wide | E. subtilis (NT) |
| Spikelets 0.75-1 mm wide | E. lacunaria (NSW VIC NT SA WA QLD) | |
| 17. | Annuals | 18 |
| Perennials | 19 | |
| 18. | Lemma 1.75-2.5 mm long; spikelet 1-1.5 mm wide | E. dielsii (NSW VIC NT SA WA QLD) |
| Lemma 1.5-1.6 mm long; spikelet 0.75-1 mm wide | E. pergracilis (NSW VIC NT SA WA QLD) | |
| 19. | Inflorescence compactly capitate, prominently exserted | E. capitula (QLD) |
| Inflorescence not capitate or exserted | 20 | |
| 20. | Inflorescence ±contracted | 21 |
| Inflorescence ±open and loose | 23 | |
| 21. | Spikelets flexuous; peduncle and inflorescence axis hirsute to pilose | E. hirticaulis (NT) |
| Spikelets rigid; peduncle and inflorescence axis glabrous |
22 | |
| 22. | Rachilla zig-zag; stamens 2 | E. filicaulis (NT WA QLD) |
| Rachilla straight; stamens 3 | E. lanicaulis (NSW NT WA QLD) | |
| 23. | Spikelets inflated, ovate to oblong | E. cassa (QLD) |
| Spikelets not inflated, lanceolate to linear | 24 | |
| 24. | Culms 70-150 cm tall; panicle 20-46 cm long | E. petraea (NT) |
| Culms to 40 cm tall; panicle to 15 cm long | 25 | |
| 25. | Culm with a thick and woolly butt | E. desertorum (NT WA QLD) |
| Culm not much thickened and only slightly woolly at base |
E. falcata (NSW VIC NT SA WA QLD) | |
| 26. | Palea up to 1/2 lemma length | E. speciosa (NSW NT SA WA QLD) E. oldfieldii |
| Palea more than 1/2 lemma length | 27 | |
| 27. | Perennials with rhizomes or conspicuously swollen butts | 28 |
| Annuals or slender perennials, scarcely thickened at base | 35 | |
| 28. | Rhizome and/or butt woolly | 29 |
| Rhizome and/or butt glabrous or sparsely pubescent (rarely woolly) |
32 | |
| 29. | Spikelets woolly-hairy | 30 |
| Spikelets glabrous | 31 | |
| 30. | Spikelets 3-5mm long | E. lanipes (NSW SA WA) E. clelandii |
| Spikelets 6-15mm long | E. laniflora (NSW NT SA WA QLD) | |
| 31. | Spikelets c. 1 mm wide | E. desertorum (NT WA QLD) |
| Spikelets at least 2 mm wide | E. eriopoda (NSW NT SA WA QLD) | |
| 32. | Inflorescence an open panicle | 33 |
| Inflorescence a contracted panicle; inhabits arid habitats | 34 | |
| 33. | Paleas deciduous; found in coastal habitats |
E. atrovirens (QLD) |
| Paleas not deciduous; inhabits inhabits inland moundsprings |
E. fenshamii (QLD) | |
| 34. | Rhizome knotty; leaf-blades flat and recurved | E. xerophila (NSW NT SA WA QLD) |
| Rhizome not knotty; leaf-blades inrolled and stiffly erect | E. setifolia (NSW VIC NT SA WA QLD) | |
| 35. | Spikelets to 1 mm wide | 36 |
| Spikelets wider than 1 mm | 41 | |
| 36. | Spikelets 1 mm long, 3-5-flowered | 37 |
| Spikelets more than 2 mm long, 4-9-flowered | 38 | |
| 37. | Slender perennial; inflorescence with ±congested branches | E. kennedyae (NSW NT SA WA QLD) |
| Annual; inflorescence ±open | E. exigua (NSW VIC NT WA QLD) | |
| 38. | Spikelets more than 4 mm long | E. leptocarpa (NSW VIC NT SA WA QLD) |
| Spikelets 2-3 mm long | 39 | |
| 39. | Inflorescence ±spiciform | E. confertiflora (NT SA WA QLD) |
| Inflorescence an open panicle | 40 | |
| 40. | Palea margins distinctly ciliate |
E. tenella (NT WA QLD) E. amabilis |
| Palea margins not ciliate | E. tenellula (NSW VIC NT SA WA QLD) E. japonica auct. |
|
| 41. | Lateral nerve of lemma distinct | 42 |
| Lateral nerve of lemma indistinct | 65 | |
| 42. | Lemma 2.5-3.5 mm long | 43 |
| Lemma less than 2.5 mm long | 44 | |
| 43. | Pedicels less than 0.5 mm long; inhabits coastal dunes | E. interrupta (NSW NT WA QLD) |
| Pedicels more than 0.5 mm long; inhabits sclerophyll woodlands and forests | E. pubescens (NSW NT WA QLD) E. stricta |
|
| 44. | Inflorescence branches with pulvini, glandular spots or rings | E. jacobsiana(QLD) |
| Branches of inflorescence without glands | 45 | |
| 45. | Inflorescence comprising more than half height of plant | E. cumingii (NT WA QLD) E. bleeseri, E. distans |
| Inflorescence comprising less than half height of plant | 46 | |
| 46. | Spikelet on pedicels 0.1-0.5 mm long | 47 |
| Spikelet on pedicels more than 0.5 mm long | 54 | |
| 47. | Spikelets arranged in an open inflorescence | 48 |
| Spikelets bunched in clusters | 49 | |
| 48. | Spikelets ± 2 mm wide | E. sterilis (NSW NT QLD) |
| Spikelets up to 1.5 mm wide | E. stenostachya (NT QLD) | |
| 49. | Rachilla disarticulating between florets | 50 |
| Rachilla not disarticulating between florets | 53 | |
| 50. | Palea prominently ciliate | E. basedowii (NSW NT SA WA QLD) |
| Palea glabrous or minutely ciliate | 51 | |
| 51. | Spikelets 1.5-2 mm wide, 6-14-flowered | E. elongata (NSW VIC NT SA WA QLD) E. contigua, E. diandra |
| Spikelets 2.2-3 mm wide, 16-36-flowered | 52 | |
| 52. | Mature spikelet at least 12 mm long | E. concinna (NT QLD) E. bella |
| Mature spikelet less than 12 mm long | E. sororia (NSW NT QLD) | |
| 53. | Spikelet ±2 mm wide | E. schultzii (WA NT QLD) |
| Spikelet ±3 mm wide | E. fallax (WA NT QLD) | |
| 54. | Spikelets ±appressed to primary branches | E. spartinoides (NSW WA NT QLD) |
| Spikelets not appressed to primary branches | 55 | |
| 55. | Inflorescence branches ciliate in their axils | *E. tef (NSW VIC SA) |
| Inflorescence branches glabrous in their axils | 56 | |
| 56. | Palea deciduous with lemmas | 57 |
| Palea not deciduous with lemmas | 59 | |
| 57. | Mature spikelet more than 3 mm wide | *E. paniciformis (QLD) |
| Mature spikelets 2-3 mm wide | 58 | |
| 58. | Annual; leaf-blades not curling up at maturity | E. unioloides (QLD) |
| Perennial; leaf-blades curling up at maturity | E. ecarinata (NT) | |
| 59. | Spikelets 0.5-1.5 mm wide | 60 |
| Spikelets more than 1.5 mm wide | 62 | |
| 60. | Spikelets ±bunched in clusters, with up to 30 florets | E. stagnalis (NT QLD) |
| Spikelets openly arranged, with up to 15 florets | 61 | |
| 61. | Perennial; spikelets on very long pedicels | E. potamophila (NT WA) |
| Annual; spikelets not on very long pedicels | *E. mexicana (NSW VIC SA WA QLD) E. neomexicana, E. virescens |
|
|
62.
63. |
Inflorescence to 4 cm long | E. subsecunda (QLD) |
| Inflorescence more than 10 cm long | 63 | |
| Basal shaeaths strongly compressed, smooth and shiny; lemma nerves prominent and with small glands | *E. plana (NSW) | |
| Basal sheaths not compressed and shiny; lemma nerves eglandular | 64 | |
| 64. | Leaf-blades to 6 mm wide, curling up at maturity | E. rigidiuscula (NT WA QLD) |
| Leaf-blades much narrower, not curling up at maturity | E. brownii (NSW VIC TAS SA WA QLD) E. benthamii, E. brownii var. patens, E. philippica, E. rara |
|
| 65. | Seed coat deep red, ridged, globose |
E. trachycarpa (NSW VIC QLD) |
| Seed coat reddish-pink to whitish, finely striate, elliptic |
66 | |
| 66. | Robust and cane-like with culms much branched | E. australasica (NSW VIC NT SA WA QLD) |
| Not robust and cane-like; culms not or sparsely branched | 67 | |
| 67. | Inflorescence ±weeping | 68 |
| Inflorescence erect | 69 | |
| 68. | Lower inflorescence branches whorled | E. parviflora (NSW VIC NT SA WA QLD) |
| Lower inflorescence branches not whorled | *E. bahiensis (QLD) | |
| 69. | Inflorescence contracted or spikelets ±contracted along inflorescence branches | 70 |
| Inflorescence a loose open panicle | 74 | |
| 70. | Inflorescence ±contracted along branches | 71 |
| Whole inflorescence ±contracted | 73 | |
| 71. | Lemma to 1mm long; rachilla internode zig-zag | E. uvida (NT QLD) |
| Lemma at least 1.5 mm long; rachilla internode straight | 72 | |
| 72. | Spikelets to 4 mm long with up to 12 fertile florets | E. microcarpa (NSW QLD) |
| Spikelets at least 5 mm long with at least 22 fertile florets | E. triquetra (NSW QLD) | |
| 73. | Lower glume 1/2 upper glume length | E. megalosperma (NSW QLD) |
| Glumes subequal | E. infecunda (VIC NT SA) | |
|
74.
75. |
Inflorescence branches ciliate in their axils | 75 |
| Inflorescence branches not ciliate in their axils | 76 | |
| Basal leaf-sheaths compressed; upper glume much shorter than adjacent lemma; leaf blades flat | *E. tenuifolia (NSW TAS NT QLD) |
|
| Basal leaf-sheaths not compressed; upper glume slightly shorter than adjacent lemma; leaf blades involute |
*E. lugens (NSW QLD) | |
| 76. | Basal sheaths densely hairy for some way from the base; spikelets olive-grey | *E. curvula (NSW VIC TAS NT SA WA QLD) |
| Basal sheaths glabrous; spikelets yellow to dark green | E. longipedicellata (QLD) |
Key to Eragrostis derived from Lazarides 1997; Palmer et al 2005
Taxonomic name: