Key to Carex Sect. Ovales West of the Rocky Mountains

1	Perigynium wings absent or entire throughout their length, 0–0.2 mm wide.		(2)
+	Perigynium wings ciliate-serrulate at least on distal body, 0.1–1 mm wide.		(3)
2 (1)	Inflorescences 1–1.2 cm; proximal internode 1.3–3 mm; perigynia wings absent, body 0.5–0.65 mm thick; marshes, bogs, wet meadows.		97 Carex illota
+	Inflorescences 1.1–2.4 cm; proximal internode (1.5–)2.5–9.5 mm; perigynia wings 0.05–0.15(–0.2) mm wide, entire, body 0.4–0.5 mm thick; seasonally moist meadows, road sides.		98 Carex integra
3 (1)	Proximal 2–3 bracts of most inflorescences elongate, ± leaflike, at least the proximal usually much longer than inflorescences; inflorescences dense, headlike.		(4)
+	Proximal 2–3 bracts of most inflorescences scalelike or bristlelike, shorter than inflorescences, the proximal sometimes leaflike, longer than inflorescence; inflorescences dense or open.		(6)
4 (3)	Achenes 0.5–0.7 mm thick, (0.9–)1–1.2(–1.4) mm wide; California.		103 Carex harfordii
+	Achenes 0.3–0.4 mm thick, 0.7–1(–1.2) mm wide; California and elsewhere.		(5)
5 (4)	Perigynia plano-convex or flat; beak usually cylindric, unwinged, ± entire at least 0.4 mm from tip; achenes sessile or shortly stipitate, near base of perigynium body; inflorescences ± erect.		99 Carex athrostachya
+	Perigynia flat around achene; beak usually flat, winged, ciliate-serrulate to tip or, sometimes, cylindric, unwinged, ± entire less than 0.4 mm; achenes stipitate, near middle of perigynium body; inflorescences usually ascending.		100 Carex unilateralis
6 (3)	Adaxial leaf sheaths thick and green-veined nearly to collar, with ± triangular white-hyaline area at collar extending at most 6 mm proximal to collar.		(7)
+	Adaxial leaf sheaths white-hyaline or green-veined with central white-hyaline strip extending at least 10 mm proximal to collar.		(8)
7 (6)	Spikes 6–12, base attenuate; leaf sheaths with rounded summit, prolonged 1.5–6 mm distal to collar; perigynia 0.4–0.5 mm thick, to 2.1 mm wide; native west of Rocky Mountains.		131 Carex feta
+	Spikes 3–5(–6), base rounded; leaf sheaths with U-shaped summit. not prolonged distal to collar; perigynia 0.5–0.6 mm thick, 2–2.8(–3) mm wide; not native west of the Rocky Mountains (introduced in California).		156 Carex molesta
8 (6)	Leaf sheaths prolonged adaxially at least 3 mm beyond collar, rounded to acute at summit; inflorescences silvery or pale green to gold.		(9)
+	Leaf sheaths prolonged adaxially less than 2.8 mm beyond collar or, if more, prolonged, summit U-shaped or inflorescences darker, gold, brown, or green and brown.		(10)
9 (8)	Perigynia (3.5–)4–5.2 mm at longest, (1.8)2–3 mm from beak tip to achene; beak flat, ciliate-serrulate to tip.		133 Carex amplectens
+	Perigynia 2.9–4(4.8) mm at longest, 1.3–2(–2.8) mm from beak tip to achene; beak cylindric, ± entire for at least 0.1 mm from tip.		132 Carex fracta
10 (8)	Perigynium body (excluding wings) flat except where distended by achene or very thinly concavo-convex.		(11)
+	Perigynium body (excluding wings) plano-convex, biconvex, or thickly concavo-convex.		(26)
11 (10)	Perignyium beak flat, ciliate-serrulate to tip; spikes distant and individually distinct.		(12)
+	Perignyium beak cylindric, unwinged, ± entire for at least 0.2 mm from tip; spikes distant or densely aggregated, individually distinct or indistinct.		(18)
12 (11)	Perigynia 0.9–1.25 mm wide, 0.15–0.3 mm thick; achenes 0.6–0.8 mm wide.		135 Carex crawfordii
+	Perigynia 1.2–3.8 mm wide, 0.35–0.7 mm thick; achenes 0.85–2 mm wide (0.7–0.9 mm in C. scoparia).		(13)
13 (12)	Perigynia lanceolate, at least 3 times as long as wide; achenes 0.7–0.9 mm wide.		134 Carex scoparia
+	Perigynia lanceolate to broadly ovate, less than 2.8 times as long as wide; achenes 0.8–2 mm wide.		(14)
14 (13)	Perigynia 5.2–7.5 mm, 0.5–0.7 mm thick, abaxial veins usually absent or obscure; pistillate scales 4.3–6.7 mm.		(15)
+	Perigynia 3.4–5.8 mm, 0.3–0.5 mm thick, abaxial at least 3 veins conspicuous; pistillate scales 3.2–5.1 mm.		(16)
15 (14)	Perigynia 2–3 mm wide, 2.4–2.7 times as long as wide; abaxial suture usually inconspicuous.		130 Carex wootonii
+	Perigynia 2.7–3.8 mm wide, 1.8–2.3 times as long as wide; abaxial suture with conspicuous white-hyaline margin.		168 Carex egglestonii
16 (14)	Perigynia 1.8–3.4 mm wide, 1.7–2.3 times as long as wide, thin, 10–20-veined abaxially, flat margin including wing 0.4– 1 mm wide, usually crinkled at least distally.		167 Carex straminiformis
+	Perigynia 1.3–2.3 mm wide, 2.2–2.6 times as long as wide, thick, 0–9-veined abaxially, flat margin including wing 0.2–0.6 mm wide, not crinkled.		(17)
17 (16)	Leaf blades becoming 3-angled toward tip, often channeled, 1–2(–3) mm wide; pistillate scales with white-hyaline margin 0.1–0.3 mm wide; perignyium beak brown to red-brown or gold, white-hyaline at tip; above 2500 m elevation.		118 Carex phaeocephala
+	Leaf blades flat ± to tip, 1.5–4 mm wide; pistillate scales without white-hyaline margin, often with white-hyaline tip or base; perignyium beak red-brown at tip, without white-hyaline; below 1100 m elevation.		115 Carex ovalis
18 (11)	Proximal inflorescence internode (2.5–)4–14 mm; spikes distant or loosely aggregated except sometimes dense in C. proposita.		(19)
+	Proximal inflorescence internode 1–4(–4.8) mm; spikes densely aggregated (sometimes proximal 1 more distant).		(22)
19 (18)	Pistillate scales 1/3–1/2 width of perigynia; perigynia margins often crinkled; anthers long-persistent.		114 Carex proposita
+	Pistillate scales 2/3–1 width of perigynia; perigynia margins flat; anthers early deciduous or short-persistent.		(20)
20 (19)	Perigynia 2.8–3.1 times as long as wide; beak cylindric, unwinged, ± entire for 0.4–1 mm from tip; inflorescences often moniliform or flexible.		117 Carex praticola
+	Perigynia 2.2–2.6 times as long as wide; beak cylindric, unwinged, ± entire for 0.3–0.6 mm from tip; inflorescences ± stiff.		(21)
21 (20)	Leaf blades becoming 3-angled toward tip, often channeled, 1–2(–3) mm wide; pistillate scales with white-hyaline margin 0.1–0.3 mm wide; perignyium beak brown to red-brown or gold with white-hyaline tip; above 2500 m elevation.		118 Carex phaeocephala
+	Leaf blades flat ± to tip, 1.5–4 mm wide; pistillate scales without white-hyaline margin, often with white-hyaline tip or base; perignyium beak red-brown or gold at tip, without white-hyaline; below 1100 m elevation.		115 Carex ovalis
22 (18)	Pistillate scales as long as perigynia, usually covering beaks; perignyium beak cylindric, unwinged, ± entire for 0.5–1.3 mm from tip; spikes 9– 12 mm.		121 Carex arapahoensis
+	Pistillate scales usually shorter than perigynia, exposing at least beaks and distal body margins; perignyium beak cylindric, unwinged, ± entire for 0.2–0.8 mm from tip; spikes 4.4–11 mm.		(23)
23 (22)	Perignyium beak usually less than 1 mm, cylindric, unwinged, ± entire for 0.5–0.8 mm from tip, body 3–8-veined adaxially.		104 Carex abrupta
+	Perignyium beak usually at least 1 mm, cylindric, unwinged, ± entire for usually less than 0.6 mm from tip, body 0–8-veined adaxially.		(24)
24 (23)	Perigynia 4–6.5 mm, usually at least (2.3–)2.6 mm from beak tip to achene; pistillate scales 3–4.8 mm; subalpine to alpine.		112 Carex haydeniana
+	Perigynia 2.4–4.5(–5.2) mm, usually no more than 2.5 mm from beak tip to achene; pistillate scales 2.4–4.1 mm; lowlands to subalpine.		(25)
25 (24)	Perigynia with glossy metallic sheen, pithlike tissue often present inside near perigynium base; leaf blades 4–18 cm; pistillate scale tips usually obtuse.		111 Carex macloviana
+	Perigynia without metallic sheen, dull to slightly shiny, pithlike tissue absent; leaf blades 10–50 cm; pistillate scale tips acute.		110 Carex microptera
26 (10)	Perigynia 0.15–0.35 mm thick, 0.9–1.25 mm wide.		135 Carex crawfordii
+	Perigynia 0.35–0.9 m thick, 1–3.4 mm wide.		(27)
27 (26)	Perigynia boat-shaped, less than 4.2 mm, with wings curved toward adaxial face, flat margins including wing 0.05–0.2 mm wide; beak tips inconspicuous in inflorescences.		120 Carex leporinella
+	Perigynia usually not boat-shaped and less than 4.2 mm, with wings adaxially incurved or, if perigynia boat-shaped and wings adaxially incurved, then flat margin including wing at least 0.2 mm wide; beak tips conspicuous in inflorescences.		(28)
28 (27)	Perigynia conspicuously veined adaxially, at least 3 veins longer than achene.		(29)
+	Perigynia essentially veinless adaxially, faintly 0–10-veined, or conspicuously 0–5-veined, veins shorter than achene.		(44)
29 (28)	Spikes densely aggregated or sometimes proximal 1 more distant; proximal inflorescence internode usually 1–4 mm.		(30)
+	Spikes distant, loosely aggregated, or closely aggregated only distally; proximal inflorescence internode 4–12 mm.		(37)
30 (29)	Perigynia usually at least 7-veined abaxially; perigynia 0.5–0.8 mm thick; achenes 1–1.7 mm wide.		(31)
+	Perigynia fewer than 7-veined abaxially or, if more than 7, perigynia 0.4–0.55 mm thick and achenes 0.6–1.3 mm wide.		(32)
31 (30)	Perigynia ovate to broadly ovate, usually more than (1.4–)1.8 mm wide, 2–2.8(–3.3) mm from beak tip to achene; inflorescences usually ± triangular, with 4–6(–10) spikes; spikes (8.5–)10–12 mm.		166 Carex multicostata
+	Perigynia lanceolate to ovate, usually less than 1.8(–2) mm wide, 2.7–4.2 mm from beak tip to achene; inflorescences usually oblong, with 5–14 spikes; spikes 9–18 mm.		126 Carex specifica
32 (30)	Perigynia 4–7.1 mm, 2.2–4 mm from beak tip to achene; pistillate scales shorter than perigynia, narrower than or ± as wide as perigynia.		(33)
+	Perigynia 1.4–5.4 mm, 1.2–2.5 mm from beak tip to achene or, if to 2.6 mm from beak tip to achene, pistillate scales ± covering perigynia.		(34)
33 (32)	Perigynia 5.3–7.1 mm; inflorescences 14–20 mm wide.		113 Carex ebenea
+	Perigynia 4–5.1 mm; inflorescences 8–15 mm wide.		109 Carex stenoptila
34 (32)	Adaxial veins of perigynia thin, extending to base of beak, beak tip reddish, coppery, or brown, (1.5–)2–2.3 mm from beak tip to achene.		(35)
+	Adaxial veins of perigynia thick, not extending beyond top of achene, beak tip white, green, gold, or brown, 1.2–2(–2.5) mm from beak tip to achene.		(36)
35 (34)	Proximal 2 inflorescence internodes collectively less than 1/3 as long as inflorescences.		104 Carex abrupta
+	Proximal 2 inflorescence internodes collectively more than 1/3 as long as inflorescences.		108 Carex mariposana
36 (34)	Perigynia 0.6–0.7 mm thick; achenes (1.3–)1.5–1.9 mm.		103 Carex harfordii
+	Perigynia 0.4–0.5(–0.6) mm thick; achenes 1–1.6 mm.		105 Carex subfusca
37 (29)	Larger perigynia 6–8.5 mm.		(38)
+	Larger perigynia less than 6 mm.		(40)
38 (37)	Staminate scales with white-hyaline margin (0-2–)0.3–0.7 mm wide; pistillate scales ± equaling, covering perigynia, white-hyaline or with white-hyaline margin 0.2–0.7 mm wide.		127 Carex petasata
+	Staminate scales with white-hyaline margin 0–0.4 mm wide; pistillate scales 2/3–3/4 length of or equaling perigynia, with white-hyaline margin 0–0.4 mm wide.		(39)
39 (38)	Spikes 2–3, 5.5–7 mm wide; pistillate scale tips acute; Sierra Nevada, California.		129 Carex davyi
+	Spikes 3–7, 7–10 mm wide; pistillate scale tips obtuse; Mount Adams, Washington.		128 Carex constanceana
40 (37)	Achenes 1–1.6 mm; perigynia 2.4–4(–4.3) mm.		105 Carex subfusca
+	Achenes 1.5–2.4 mm; perigynia 3.4–6 mm.		(41)
41 (40)	Pistillate scales white or tinged pale gold; inflorescences 40– 65 mm; proximal internode 7–20 mm; 2d internode 4–8.5 mm.		133 Carex amplectens
+	Pistillate scales gold to brown, often reddish, with white-hyaline margin 0–0.6 mm wide; inflorescences 15–40 mm; proximal internode 3.5–11 mm; 2d internode 2–7 mm (inflorescences to 48 mm; proximal and 2d internode 3.5–7.5 and 2.5–5 mm, respectively, in C. mariposana).		(42)
42 (41)	Perigynia appressed or appressed-ascending, (0.6–)1–2 mm from beak tip to achene; pistillate scales with white margin 0.2–0.6 mm wide; achenes 0.5–0.7 mm thick.		119 Carex tahoensis
+	Perigynia ascending, 1.5–2.6 mm from beak tip to achene; pistillate scales with white-hyaline margin 0–0.3 mm wide; achenes 0.3–0.6 mm thick.		(43)
43 (42)	Perigynia 1.5–2.3 mm wide, flat margin including wing 0.3–0.5 mm wide, beak sometimes white-hyaline at tip; pistillate scales lanceolate to ovate, usually ± covering perigynia.		118 Carex phaeocephala
+	Perigynia 1.1–1.6(–2.2) mm wide, flat margin including wing 0.15–0.4 mm wide, beak tip not white-hyaline; pistillate scales ovate to broadly ovate, usually shorter than perigynia.		108 Carex mariposana
44 (28)	Perignyium beak flat, ± ciliate-serrulate to tip or cylindric, unwinged, ± entire for less than 0.4 mm from tip.		(45)
+	Perignyium beak cylindric, unwinged, ± entire for at least 0.4 mm from tip.		(57)
45 (44)	Perigynia broadly ovate to orbiculate, 1.2–1.8 times as long as wide.		(46)
+	Perigynia narrowly to broadly ovate or elliptic, 1.9–2.7 times as long as wide.		(47)
46 (45)	Spikes on larger culms 5–7, base attenuate, terminal spike with conspicuous staminate base; inflorescences usually 25–50 mm; achenes 1.3–1.8 mm wide.		154 Carex brevior
+	Spikes on larger culms mostly 3–4, base rounded, terminal spike without conspicuous staminate base; inflorescences 13–35 mm; achenes 0.9–1.3 mm wide.		156 Carex molesta
47 (45)	Proximal inflorescence internode usually 1–4 mm; spikes densely aggregated.		(48)
+	Proximal inflorescence internode at least 3 mm; spikes distant or loosely aggregated.		(51)
48 (47)	Perigynia reddish brown, 0.35–0.45 mm thick, 1.9–2.1 times as long as wide; achenes 0.6–0.9 mm wide.		150 Carex bebbii
+	Perigynia green, straw colored, gold, light to coppery brown, or whitish, 0.4–0.7 mm thick, 2.1–2.7 times as long as wide; achenes 0.7–1.5 mm wide.		(49)
49 (48)	Achenes 1–1.6 × 0.7–1.25 mm; inflorescences appearing fine-textured.		105 Carex subfusca
+	Achenes 1.3–2 × 0.9–1.5 mm; inflorescences appearing more coarse-textured.		(50)
50 (49)	Proximal inflorescence internode 1.5–2.5 mm; 2d internode 1–2.5 mm; adaxial leaf sheaths usually brown- or gold tinged near summit; coastal California to 600 m elevation.		103 Carex harfordii
+	Proximal inflorescence internode 3–7 mm; 2d internode 1–4 mm; adaxial leaf sheaths white-hyaline; inland West 1000-3400 m elevation.		107 Carex preslii
51 (47)	Achenes 1–1.7(1.9) mm; pistillate scales usually 2.1–3.5 mm; perigynia less than 4.5 mm.		(52)
+	Achenes 1.5–2.7 mm; pistillate scales 2.8–6.2 mm; perigynia 3.3–7.5 mm.		(53)
52 (51)	Perigynia 2–2.3 times as long as wide, brown; culms often nodding; inflorescences (20–)25–50 mm, often flexible; 2d internode (3–)6–10 mm.		152 Carex tenera
+	Perigynia 2.1–2.7 times as long as wide, green, straw colored, or light brown, often white over achene; culms not nodding; inflorescences 11– 30 mm, not flexible; 2d internode 1–6 mm.		105 Carex subfusca
53 (51)	Perigynia 5.4–7.5 mm, flat margin including wing 0.5–0.8 mm wide; achenes 1.4–2 mm wide.		130 Carex wootonii
+	Perigynia 3.3–5.2 mm or, if longer, flat margin including wing less than 0.5 mm wide; achenes (0.8–)1–1.3(–1.7) mm wide.		(54)
54 (53)	Inflorescences flexible; spikes usually distant; proximal 2 internodes collectively 9–37 mm; perigynia 0.6–0.8 mm thick.		123 Carex foenea
+	Inflorescences stiff; spikes aggregated to distant; proximal 2 internodes collectively 4–18 mm; perigynia 0.4–0.6 mm thick (to 0.8 mm thick in Carex preslii, which has proximal 2 inflorescence internodes collectively 4–11 mm).		(55)
55 (54)	Perigynia essentially erect, faintly 8–10-veined abaxially.		125 Carex xerantica
+	Perigynia appressed-ascending to ascending-spreading, conspicuously 0–8-veined abaxially.		(56)
56 (55)	Spikes 7–10 mm; perigynia biconvex or plano-convex, flat margin including wing 0.2–0.4 mm wide.		107 Carex preslii
+	Spikes 12–15 mm; perigynia flat or plano-convex, flat margin including wing 0.3–0.5 mm wide.		118 Carex phaeocephala
57 (44)	Perigynia 2.9–4 mm from beak tip to achene, 0.4–0.5 mm thick; pistillate scales shorter than perigynia, exposing upper margins and beaks; beak tip similar in color to beak or sometimes gold-hyaline.		113 Carex ebenea
+	Perigynia less than 2.9 mm from beak tip to achene or, if to 3 mm, then 0.5–0.8 mm thick and pistillate scales covering perigynia; beak tip white-hyaline.		(58)
58 (57)	Perigynia thick-walled ± leathery, with metallic sheen.		(59)
+	Perigynia thin-walled, not leathery, with or without metallic sheen.		(60)
59 (58)	Spikes densely aggregated, individually indistinct, sometimes proximal 1–3 distant; proximal inflorescence internode 2–3(–4.5) mm; spike bases rounded.		101 Carex subbracteata
+	Spikes usually distant to loosely aggregated, at least proximal 1–3 distinct; proximal inflorescence internode 2.5–7 mm; spike bases acute to attenuate.		102 Carex gracilior
60 (58)	Perignyium beak with apex white-hyaline, abaxial suture white-hyaline.		(61)
+	Perignyium beak with apex and abaxial suture similar in color to beak or gold- or brown-hyaline.		(64)
61 (60)	Pistillate scales less than 3.7 mm; perigynia with glossy metallic sheen; proximal inflorescence internode 0.7–4.5(–9) mm.		(62)
+	Pistillate scales at least 3.7 mm; perigynia without glossy metallic sheen; proximal inflorescence internode 4–14 mm.		(63)
62 (61)	Perigynia 0.4–0.5 mm thick, wings dark, conspicuously contrasting with body color.		111 Carex macloviana
+	Perigynia 0.5–0.7 mm thick, wings similar in color to body, at most dark-edged.		106 Carex pachystachya
63 (61)	Perigynia 0.4–0.5 mm thick; 2d inflorescence internode usually 2– 5 mm; subalpine to alpine.		118 Carex phaeocephala
+	Perigynia 0.5–0.8 mm thick; 2d inflorescence internode usually 4– 10 mm; lowlands to subalpine.		117 Carex praticola
64 (60)	Achenes 1–1.6 mm; inflorescences appearing fine-textured.		105 Carex subfusca
+	Achenes (1.3–)1.5–2 mm; inflorescences appearing rather coarse-textured.		(65)
65 (64)	Spikes densely aggregated, individually indistinct; proximal 2 inflorescence internodes collectively less than 1/3 length of inflorescences.		(66)
+	Spikes distant to loosely aggregated, individually distinct or, if ± densely aggregated; proximal 2 inflorescence internodes collectively more than 1/3 length of inflorescences.		(67)
66 (65)	Perigynia green or straw colored to light brown (coppery); beak tip gold or brown.		103 Carex harfordii
+	Perigynia gold or coppery to blackish; beak tip red-brown or black.		106 Carex pachystachya
67 (65)	Perigynia biconvex to plano-convex, without metallic sheen, usually green to- ward beak, contrasting in color with pistillate scales.		107 Carex preslii
+	Perigynia plano-convex, with metallic sheen, usually not green toward beak, ± similar in color to pistillate scales.		106 Carex pachystachya