1	Male spike linear, shorter than 3 cm; female glumes ovate or broadly ovate, shorter than 1/2 length of utricle, muticous at apex		(2)
+	Male spike cylindric, narrowly cylindric, or clavate, usually longer than 3 cm (rather short in C. brownii and C. transversa); female glumes narrowly ovate, oblong, or lanceolate, longer than 2/3 length of utricle or much more, mucronate or aristate at apex		(3)
2 (1)	Female glumes broadly ovate; utricles suberect or slightly obliquely patent, ovate-oblong, ca. 4 mm; male flower with 3 stamens.		255 C. ischnostachya
+	Female glumes ovate; utricles nearly horizontally patent, elliptic or obovate, ca. 3 mm; male flower with 1 stamen.		256 C. subtumida
3 (1)	Utricles hispidulous		(4)
+	Utricles smooth, glabrous		(5)
4 (3)	Leaf blades 6-8 mm wide; spikes contiguous at top of culm; female glumes attenuate at apex, long aristate; utricles ca. 3 mm, equaling glume, dark brown, beak usually recurved.		257 C. nemostachys
+	Leaf blades 3-6 mm wide; spikes remote; female glumes mucronate at apex; utricles 2-2.8 mm, longer than glume, brown-green, beak straight.		258 C. sclerocarpa
5 (3)	Culms lateral; female glumes dark purple-red		(6)
+	Culms central; female glumes usually pale, greenish or brownish		(7)
6 (5)	Female glumes awned, ca. 5 mm; nutlets ellipsoid.		259 C. retrofracta
+	Female glumes emarginate, 2-2.5 mm; nutlets obovoid.		260 C. obliquicarpa
7 (5)	Female spikes cylindric-oblong, 1-2 cm; utricles distinctly many veined		(8)
+	Female spikes long cylindric, longer than 3 cm, longest up to 10 cm; utricles few veined		(10)
8 (7)	Utricles broadly obovate, ca. 3 mm, apex abruptly contracted into a short beak.		261 C. brownii
+	Utricles oblong-ovate, 4-6 mm, apex gradually narrowed to a long beak		(9)
9 (8)	Utricles distinctly stipitate, 2-toothed at orifice.		262 C. benkei
+	Utricles broadly cuneate at base, obliquely truncate or minutely 2-toothed at orifice.		263 C. transversa
10 (7)	Male spike linear or linear-cylindric; female glumes ovate, awned at apex, length of awn 1-2.5 × as long as utricle; utricles suberect or slightly obliquely patent at maturity, brown-green, beak straight		(11)
+	Male spike rather thick, long cylindric; female glumes lanceolate or oblong-lanceolate, mucronate or aristate at apex, awn shorter than 1/2 length of glume (C. olivacea with female glumes sometimes with long awn, slightly longer than 1/2 length of glume); utricles obliquely patent to ± horizontally patent, sometimes reflexed downward, dark brown or nearly black-brown, rarely yellow-brown, beak ± recurved		(12)
11 (10)	Male spike 6-14 cm; female spikes 6-14 cm; utricles ovate, ca. 3 mm, with medium-sized beak.		264 C. oedorrhampha
+	Male spike 2.5-3 cm; female spikes 2.5-5.5 cm; utricles broadly ovate, ca. 4 mm, with rather long beak.		265 C. sinoaristata
12 (10)	Female spikes rather remote, loosely flowered; utricles horizontally patent or slightly reflexed downward, nearly black-brown, beak distinctly recurved.		266 C. recurvisaccus
+	Female spikes contiguous at top of culm, densely many flowered; utricles obliquely patent or nearly horizontally patent, not reflexed downward, yellow-brown or dark brown, beak slightly recurved		(13)
13 (12)	Leaf blades 8-18 mm wide; female spikes usually with few male flowers at upper part; utricles inflated trigonous, ca. 4 mm; nutlets subloosely enveloped.		267 C. olivacea
+	Leaf blades 4-8(-12) mm wide; female spike without male flowers; utricles not inflated trigonous or slightly inflated trigonous, ca. 3 mm; nutlets rather tightly enveloped		(14)
14 (13)	Leaf blades 8-12 mm wide; female glumes dark brown, rather long aristate; utricles dark brown at maturity, irregularly rugose or ± verrucose.		268 C. confertiflora
+	Leaf blades 4-8 mm wide; female glumes purple-red on margins, mucronate or aristate; utricles brown-yellow at maturity		(15)
15 (14)	Utricles with transverse rugae at maturity, beak purple-red at upper part; nutlets stramineous.		269 C. dispalata
+	Utricles smooth at maturity, beak red-brown at upper part; nutlets dark brown.		270 C. pseudodispalata