Leaves with ligule a rim of minute hairs or rarely membranous; blade flat, narrow, convolute, rolled in the bud, rarely absent.
Spikelets solitary, pedicellate; 3–many bisexual florets, usually closely imbricate; rachilla disarticulating above the glumes and between the lemmas, or persistent with the lemmas deciduous and the paleas subpersistent. Glumes unequal, acute or acuminate, membranous, 1-nerved or the upper rarely 3-nerved, keeled. Lemmas acute or acuminate, 3-nerved with the lateral nerves faint, keeled or rounded on the back, overlapping, margins rarely ciliate. Palea equal to the lemma, 2-keeled, keel sometimes ciliate.
Eragrostis tef (Zucc.)Trotter commonly known as 'Tef Millet' and Eragrostis tephrosanthes Schult. may have become naturalised locally in NSW.
| | Key to the species | |
| 1 | Perennials with swollen stem bases covered by numerous hairy or glabrous cataphylls, often also with short to long, thick, knotty rhizomes | 2 |
| Perennials or annuals, without conspicuously swollen stems or bases, rhizomes usually absent, never thick and knotty | 9 |
| 2 | Coarse almost shrubby perennials up to or more than 2 m tall, branching along the stem and with few foliage leaves; lateral nerves of lemma subequal to midvein, all 3 fading halfway along the lemma | Eragrostis australasica |
| Plants less than 1 m high, rarely branching from upper nodes and with numerous foliage leaves; lateral nerves of lemma shorter than the midvein
Back to 1 | 3 |
| 3 | Lemmas hairy along the lower margins | Eragrostis laniflora |
| Lemmas glabrous
Back to 2 | 4 |
| 4 | Leaves flat, even when dry, almost distichous (in 2 rows) | Eragrostis xerophila |
| Leaves rarely flat, normally rolled, always rolled when dry
Back to 3 | 5 |
| 5 | Plants with thick woolly swollen bases, infloresence sparsely branched often more or less spike-like, the spikelets spreading or curving away from the axis at maturity | 6 |
| Plants with swollen bases but these glabrous or hairy, not covered by thick woolly hairs; inflorescence often branched, rarely reduced and spike-like but then with some florets obviously aborted; spikelets rarely spreading or curving away from the axis at maturity
Back to 4 | 8 |
| 6 | Lemmas 1–1.5 mm long | Eragrostis desertorum |
| Lemmas 1.7–3 mm long
Back to 5 | 7 |
| 7 | Lemmas 2–3 mm long; palea keeled for almost whole length; floret usually falling with fragile rachilla joint | Eragrostis eriopoda |
| 7 | lemmas 1.7–2 mm long; palea keels shorter tahn body of palea; rachilla and palea persistent | Eragrostis lanicaulis |
| 8 | Mature spikelets c. 1 mm wide, usually with more than 20 florets; lemmas less than 2 mm long | Eragrostis falcata |
| Mature spikelets more than 1.5 mm wide, usually with less than 20 florets; lemmas c. 2 mm long
Back to 5 | Eragrostis setifolia |
| 9 | Inflorescence an open panicle, to twice as long as broad or 8 cm or more wide | 10 |
| Inflorescence more or less compact, usually more than twice as long as broad (sometimes reduced by environmental conditions) or less than 6 cm wide
Back to 1 | 30 |
| 10 | Annuals (mature plants pull up easily) | 11 |
| Perennials (mature plants cannot be pulled up easily)
Back to 9 | 17 |
| 11 | Plants usually more than 50 cm high, spikelets with 10–20 florets, 1 mm wide; lemmas 1.5 mm long; panicle 20–30 cm long, more or less drooping | Eragrostis parviflora |
| Plants usually less than 50 cm high or spikelets more than 1 mm wide; lemmas more than 1.5 mm long and inflorescence less than 20 cm long
Back to 10 | 12 |
| 12 | Leaves with marginal glands and/or inflorescence with a brown ring below the lower nodes (= 'ring of glands') | 13 |
| Leaves without marginal glands; inflorescences without glands; glands sometimes present elsewhere on the sheath or blade
Back to 11 | 16 |
| 13 | Spikelets 2–4 mm wide, lemmas usually more than 2 mm long | Eragrostis cilianensis |
| Spikelets 1–2 mm wide, if c. 2 mm wide then the lemmas 2 mm long or less
Back to 12 | 14 |
| 14 | Palea keels shorter than body of the palea | Eragrostis pilosa |
| Palea keels as long as the body of the lemma
Back to 13 | 15 |
| 15 | Lemmas scabrous | Eragrostis barrelieri |
| Lemmas smooth
Back to 14 | Eragrostis minor |
| 16 | Spikelets < 1.5 mm wide | Eragrostis pilosa |
| Spikelets > 1.5 mm wide
Back to 12 | Eragrostis mexicana |
| 17 | Axils of inflorescence branches with fine long hairs | 18 |
| Inflorescence with axils of secondary and subsequent branches glabrous, axils of primary barnches may have hairs
Back to 10 | 20 |
| 18 | Axils of pedicels also hairy | Eragrostis tenuifolia |
| Hairs restricted to axils of main inflorescence branches
Back to 17 | 19 |
| 19 | Inflorescence large and robust; lemma >2 mm long; grain obtuse | Eragrostis curvula |
| Inflorescence open and delicate; lemmas <2 mm long; grain truncate
Back to 18 | Eragrostis lugens |
| 20 | Spikelets with 3–5 florets, pedicels 2–6 times the length of the spikelet | Eragrostis trachycarpa |
| Spikelets with more than 5 florets or with relatively shorter pedicels
Back to 17 | 21 |
| 21 | Lemmas >2 mm long | 22 |
| Lemmas <2 mm long
Back to 20 | 24 |
| 22 | Grain twice as long as broad | Eragrostis curvula |
| Grain sub-globose
Back to 21 | 23 |
| 23 | Grain truncate, spikelets leaden-green, flattened, 1.5 mm or wide | Eragrostis alveiformis |
| Grain ovoid, spikelets purple or straw-coloured, slightly flattened, c. 1 mm wide
Back to 22 | Eragrostis falcata |
| 24 | Axils of primary branches pilosa with hairs 1–3 mm long | Eragrostis lugens |
| Axils of primary branches glabrous or with hairs <1 mm long
Back to 21 | 25 |
| 25 | Spikelets terete, narrow, >4 mm long; lateral nerves of lemma closer to the margin than the midvein | Eragrostis lacunaria |
| Spikelets flattened; lateral nerves of lemma usually half way between margins and midvein
Back to 24 | 26 |
| 26 | Main inflorescence branches above the lowest whorl mostly opposite | 27 |
| Main inflorescence branches above the lowest whorl mostly alternate
Back to 25 | 28 |
| 27 | Grain twice as long as broad, lemma 1.75–2 mm long | Eragrostis leptocarpa |
| Grain sub-globose, lemma 1.5 mm long
Back to 26 | Eragrostis parviflora |
| 28 | Grain truncate, spikelets leaden-green, lemmas 1.5–1.75 mm long, opaque | Eragrostis leptostachya |
| Grain obtuse, lemmas 1–2 mm long
Back to 26 | 29 |
| 29 | Lemmas <1.5 mm long, translucent | Eragrostis microcarpa |
| Lemmas >1.5 mm long, opaque, leaden-green or rarely straw-coloured
Back to 28 | Eragrostis benthamii |
| 30 | Annuals (plants pull up easily) | 31 |
| Perennials (plants hard to pull up)
Back to 9 | 35 |
| 31 | Spikelets <5 mm long and >1 mm wide with <5 florets; delicate annual | Eragrostis tenuella |
| Spikelets >5 mm long or >1 mm wide, usually with >5 florets
Back to 30 | 32 |
| 32 | Leaves with marginal glands and/or inflorescence with a brown ring below the nodes (='ring of glands') | 33 |
| Leaf margins and inflorescence without glands
Back to 31 | 34 |
| 33 | Spikelets 2–4 mm wide; lemmas usually >2 mm long | Eragrostis cilianensis |
| Spikelets 1.5–2 mm wide; lemmas usually <2 mm long
Back to 32 | Eragrostis barrelieri |
| 34 | Spikelets flattened, greater than or equal to 3 mm wide; palea with obvious hairs 0.5 mm long on the keels | Eragrostis basedowii |
| Spikelets sub-terete, < 2 mm wide; palea without obvious hairs
Back to 32 | Eragrostis dielsii |
| 35 | Spikelets <2 mm wide | 36 |
| Spikelets >2 mm wide
Back to 30 | 43 |
| 36 | Spikelets less than or equal to 1 mm with 3 florets | Eragrostis kennedyae |
| Spikelets >2 mm long
Back to 35 | 37 |
| 37 | Spikelets sub-terete or cylindrical | 38 |
| Spikelets distinctly flattened
Back to 36 | 39 |
| 38 | Spikelets 1.2–2.5 mm wide, lemmas 1.75 mm long, grain 0.6–0.7 mm long; plant more or less scabrous | Eragrostis dielsii |
| Spikelets 1–1.2 mm wide, lemmas less than 1.75 mm long, grain slightly less than 0.6 mm long; plant smooth
Back to 37 | Eragrostis pergracilis |
| 39 | Grain truncate; inflorescence more or less open | Eragrostis leptostachya |
| Grain obtuse; inflorescence narrow, branches mostly erect
Back to 37 | 40 |
| 40 | Lemma <1.4 mm long; usually <8 florets/spikelets | Eragrostis trichophora |
| 40 | Lemma greater than or equal to 1.4 mm long; usually >9 spikelets/floret | 41 |
| 41 | Rachilla straight | Eragrostis speciosa |
| Rachilla flexuose or zigzag
Back to 40 | 42 |
| 42 | Palea c. 50% the length of the lemma; palea flaps distinctly narrower than the body of the palea; caryopsis c. 0.5 mm long | Eragrostis sterilis |
| Palea > 50 % the length of the lemma; palea flaps wider thant the body of the palea; capyopsis 0.9–1 mm long
Back to 41 | Eragrostis megalosperma |
| 43 | Spikelets 3–8 mm long in dense sessile or sub-sessile clusters along the axis of an interrupted spike-like panicle | Eragrostis elongata |
| Spikelets scattered on short panicle branches, the lower branches at least as long as the spikelets or in pedunculate (stalked) clusters
Back to 35 | 44 |
| 44 | Branches of the panicle shortly pubsecent on upper surfaces for several millimetres from their axils | Eragrostis pubescens |
| Branches of the panicle glabrous or hispid, not pubsecent
Back to 43 | 45 |
| 45 | Rachilla persistent, lemmas falling fast | Eragrostis spartinoides |
| Florets falling as a unit, rachilla persistent
Back to 44 | 46 |
| 46 | Palea 50% the lenght of the lemma | 47 |
| Palea 75% or more the length of the lemma
Back to 45 | 48 |
| 47 | Rachilla straight | Eragrostis speciosa |
| Rachilla flexuose or zig-zag
Back to 46 | Eragrostis sterilis |
| 48 | Upper glume 2.5–3 mm long; spikelets in subsessile clusters; lower inflorescence branches 1–3 times as long as the spikelets | Eragrostis interrupta |
| Upper glume 1.5–2 mm long; spikelets borne on lateral branches, lower lateral branches 2-several times as long as the spikelets
Back to 46 | 49 |
| 49 | Lemmas 1.5–2 mm long, the paleas with the 2 keels narrowing and almost meeting at the apex, pedicels of spikelets very short | Eragrostis brownii |
| Lemmas c. 2.5 mm long, the paleas with a broad membranous connection at the apex between the 2 keels
Back to 48 | Eragrostis sororia |
