1	"Awn absent (the awns of some species are readily deciduous, so many spikelets should be examined)."	2
1	"Awn present."	3
2	"Leaves 2–4 cm long, mostly in tufts at the base of the plant; panicle narrow, 2–5 cm long, spikelets 2–2.5 mm long."	"Deyeuxia innominata"
2	"Leaves 4–10 cm long with many leaves on stems; panicle open to slightly contracted, 5–10 cm long; spikelets 3–3.5 mm long."	"Deyeuxia nudiflora"
3	"Awn arising from lower 35% of lemma."	4
3	"Awn arising from upper 65% of lemma."	5
4	"Lower glume slightly longer than upper glume or glumes equal; lemmas with 4 long teeth at apex; rachilla not usually prolonged beyond floret; panicle lobed or linear, dense."	"Deyeuxia quadriseta"
4	"Lower glume slightly shorter than upper glume; lemma teeth variable; rachilla prolonged beyond floret and may bear a second floret; panicle dense to moderately contracted."	"Deyeuxia monticola"
5	"Awn arising about the middle of the lemma."	6
5	"Awn arising in top 30% of lemma (subterminal)."	11
6	"Panicle less than 15 cm long."	7
6	"Panicle 15 cm or more in length."	9
7	"Spikelets 3.5 mm long or less; awn less than 3 mm long; panicle somewhat contracted; slender plant."	"Deyeuxia rodwayi"
7	"Spikelets 4 mm or more in length; awn 3–4 mm long."	8
8	"Spikelets 5 mm or more in length; panicle cylindrical, dense; rachilla produced as a glabrous bristle; leaves with hard tip; decumbent plant."	"Deyeuxia carinata"
8	"Spikelets c. 4–5 mm long; panicle more open; rachilla produced as a hairy bristle; leaves not hard-tipped; slender plant."	"Deyeuxia accedens"
9	"Spikelets c. 3 mm long; awn 1–2 mm long, straight; panicle moderately dense, often lobed; erect plants."	"Deyeuxia mesathera"
9	"Spikelets 3.5 mm or more in length; awn 3 mm long; panicle open and spreading; robust plants."	10
10	"Glumes unequal, the lower c. 75% the length of the upper; spikelets 4.5–5.5 mm long; awn longer than lemma."	"Deyeuxia frigida"
10	"Glumes equal or subequal; spikelets 3.5–4.5 mm long; awn only just exceeding the lemma."	"Deyeuxia benthamiana"
11	"Awn short, less than 1 mm long and not usually projecting beyond lemma apex (if awn projects then spikelets 2 mm or less in length)."	12
11	"Awn more than 1 mm long and projecting beyond the lemma."	21
12	"Lemma longer than both glumes."	13
12	"Lemma shorter than lower glume and often shorter than both glumes."	15
13	"Panicle short, 2–9 cm long, narrow but not dense, with short, stiff branches; plants delicate, not usually more than 30 cm high."	"Deyeuxia gunniana"
13	"Panicle larger, 12–20 cm long, open and spreading with long branches; plants more than 30 cm high, usually erect and fairly robust."	14
14	"Panicle 12–30 cm long; spikelets c. 2.5 mm long, a second floret sometimes present on prolonged rachilla (var. parviseta)."	"Deyeuxia parviseta"
14	"Panicle 20–40 cm long; spikelets c. 3.5 mm long."	"Deyeuxia mckiei"
15	"Rachilla produced beyond the floret as a glabrous bristle or absent."	16
15	"Rachilla produced beyond the floret as a hairy bristle."	19
16	"Spikelets 4 mm or more long; callus glabrous; plant slender."	"Deyeuxia angustifolia"
16	"Spikelets less than 4 mm long; callus hairy; erect plants."	17
17	"Panicle very dense, linear; lemma truncate and minutely 4-toothed at apex."	"Deyeuxia imbricata"
17	"Panicle more open, often spreading; lemma tip obtuse, acute or toothed."	18
18	"Panicle open, spreading and usually large, 12–30 cm long, nerves of lemma conspicuous; lemma not conspicuously scaberulous; rachilla bristle often absent."	"Deyeuxia decipiens"
18	"Panicle more contracted, 7–20 cm long, linear-lanceolate in outline; nerves of lemma inconspicuous; lemma scaberulous."	"Deyeuxia contracta"
19	"Spikelets less than 3 mm long (var. boormanii)."	"Deyeuxia parviseta"
19	"Spikelets 3 mm or more in length."	20
20	"Panicle short, 6–9 cm long; glumes subequal; lemma not obviously scaberulous."	"Deyeuxia microseta"
20	"Panicle longer, usually 9 cm or more in length; lemma distinctly scaberulous (light hairs on a darker surface); glumes unequal."	"Deyeuxia scaberula"
21	"Spikelets 4 mm or more in length."	22
21	"Spikelets less than 4 mm long."	24
22	"Panicle large and spreading, 20–60 cm long, with long, bare branches; robust plant."	"Deyeuxia acuminata"
22	"Panicle narrow and denser, 6–18 cm long, with spikelets towards the bases of the branches."	23
23	"Awns 1–2 mm long, straight; panicle short, dense, 6–8 cm long; short grass."	"Deyeuxia crassiuscula"
23	"Awns 4–5 mm long; curved, panicle fairly dense, 8–18 cm long; erect plant."	"Deyeuxia brachyathera"
24	"Panicle large, open, c. 20 cm long; lemma longer than glumes; erect plant."	"Deyeuxia reflexa"
24	"Panicle moderately open to contracted; lemma shorter than the glumes; plants erect or spreading."	25
25	"Panicle 20–30 cm long, linear to lobed; awn 3–5 mm long; erect plant."	"Deyeuxia appressa"
25	"Panicle 2–6 cm long, contracted, cylindrical; awn 1.5 mm long; short alpine grass"	"Deyeuxia affinis"