1	Awn scabrid or minutely hispidulous (hairs to 0.3 mm) throughout		(2)
+	Awn plumose or at least shortly hairy along part or all of its length		(8)
2 (1)	Cleistogamous spikelets present in basal leaf sheaths; lemma 0.5–0.6 cm.		1 S. bungeana
+	Cleistogamous spikelets not present in basal leaf sheaths; lemma 0.8–1.7 cm		(3)
3 (2)	Panicle branches not enclosed by uppermost leaf sheath, usually clearly exserted; awn minutely hispidulous, bristle straight or slightly flexuous		(4)
+	Panicle branches enclosed by expanded uppermost leaf sheath; awn scabrid, bristle curling		(5)
4 (3)	Glumes 1.2–1.5 cm, apex finely acuminate; awns separate, bristle stiff.		2 S. przewalskyi
+	Glumes 1.5–3 cm, apex filamentous; awns twisted together at top of panicle, bristle flexuous.		3 S. capillacea
5 (3)	Glumes 1.8–2.5 cm; awn column 1.5–2.5 cm to first bend.		4 S. sareptana
+	Glumes 2.5–4.5 cm; awn column 3–10 cm to first bend		(6)
6 (5)	Ligule of culm leaves 1.5–2 mm.		5 S. baicalensis
+	Ligule of culm leaves 3–10 mm		(7)
7 (6)	Lemma 1–1.2 cm; awn 13–18 cm.		6 S. capillata
+	Lemma 1.5–1.7 cm; awn 20–28 cm.		7 S. grandis
8 (1)	Awn plumose, or at least shortly hairy, throughout its length		(9)
+	Awn plumose only on column or only on bristle		(16)
9 (8)	Awn 1-geniculate (sometimes weakly 2-geniculate in S. consanguinea)		(10)
+	Awn 2-geniculate		(12)
10 (9)	Awn shortly pubescent, hairs on bristle 0.4–0.7 mm.		9 S. consanguinea
+	Awn plumose, hairs on bristle 2–5 mm		(11)
11 (10)	Panicle shortly exserted; lemma evenly hairy.		10 S. mongolorum
+	Panicle branches enclosed by uppermost leaf sheath; lemma hairs in lines.		11 S. caucasica
12 (9)	Lemma hairs in lines; glumes gray-green or pale brownish, narrowly lanceolate, long attenuate-filiform		(13)
+	Lemma evenly hairy; glumes green or dark purple, lanceolate, acuminate into awn-point		(15)
13 (12)	Glumes 1.8–3 cm; lemma smooth or scaberulous below apex; awn hairs 1–4 mm		(14)
+	Glumes 1.2–2 cm; lemma spinulose below apex; awn hairs 0.8–1.5 mm.		14 S. breviflora
14 (13)	Culms 15–35 cm; awn 4–6 cm, hairs on bristle 3–4 mm.		12 S. orientalis
+	Culms 40–80 cm; awn 9–20 cm, hairs on bristle 1–2.5 mm.		13 S. arabica
15 (12)	Panicle branches 3–6 cm, flexuous; glumes dark purple; awn 6.5–9 cm, hairs shorter below, 2–3 mm on bristle.		15 S. purpurea
+	Panicle branches 2–4 cm, straight; glumes green or purplish; awn 3–6 cm, hairs longer below, 0.3–0.7 mm on bristle.		16 S. roborowskyi
16 (8)	Awn 1.5–3 cm; column plumose, bristle glabrous or minutely hairy (hairs 0.1–0.2 mm)		(17)
+	Awn 6–28 cm; column glabrous, bristle plumose, hairs 2–6 mm		(20)
17 (16)	Panicle 1–2 cm wide; branches 1–3 cm, suberect		(18)
+	Panicle (2–)3–7 cm wide; branches 3–6 cm, spreading or obliquely ascending		(19)
18 (17)	Awn obscurely 2-geniculate, hairs on column up to 1 mm; spikelets 1.1–1.4 cm.		17 S. regeliana
+	Awn distinctly 2-geniculate, hairs on column 2–3 mm; spikelets 0.6–1.1 cm.		18 S. subsessiliflora
19 (17)	Leaf blades scabrid or hairy; panicle branches spreading, with cushion in axils; ligule 3–7 mm; column hairs 3–4 mm.		19 S. penicillata
+	Leaf blades smooth, glabrous; panicle branches ascending, without cushion in axils; ligule 1–1.5 mm; column hairs 1–2 mm.		20 S. aliena
20 (16)	Awn 1-geniculate, 6–13 cm.		8 S. tianschanica
+	Awn 2-geniculate, 15–28 cm		(21)
21 (20)	Glumes 2–3 cm; lemma evenly hairy; awn hairs 2–3 mm.		21 S. lessingiana
+	Glumes 3–5.5 cm; lemma hairs in lines; awn hairs 3–6 mm		(22)
22 (21)	Column of awn 5–6 cm to first bend; ligule up to 4 mm.		22 S. kirghisorum
+	Column of awn 3.5–4.5 cm to first bend; ligule 4–12 mm.		23 S. macroglossa