1 |
Proximal leaf sheaths longitudinally green-and-white-striped and with prominent green cross veins, usually loose; widest leaf blade 3–10 mm wide. |
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(2) |
+ |
Proximal leaf sheaths not or indistinctly striped, without prominent cross veins, tight; widest leaf blade 0.5–4(–5) mm wide. |
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(5) |
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2 (1) |
Bodies of pistillate scales 2.2–4.4 × 1.2–2.4 mm, mostly more than 1/2 length of perigynia, apex acuminate to awned; anthers 1.5–3 mm. |
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(3) |
+ |
Bodies of pistillate scales 1.5–2.5 × 1.1–1.8 mm, mostly less than 1/2 length of perigynia, apex obtuse to acuminate or shortly awned; anthers 0.7–1.3 mm. |
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(4) |
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3 (2) |
Fronts of leaf sheaths white, hyaline, thin, and fragile at mouth, backs not white spotted. |
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42 Carex gravida |
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Fronts of leaf sheaths yellow or brown, thick, and firm at mouth, backs often white spotted. |
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43 Carex aggregata |
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4 (2) |
Proximal internodes of inflorescences usually not more than 1 cm, usually less than 2 times as long as proximal spikes; bodies of perigynia with narrow wing not more than 0.1 mm wide. |
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44 Carex cephaloidea |
+ |
Proximal internodes of inflorescences usually 2+ cm, at least 2 times as long as proximal spikes; bodies of perigynia with narrow wing 0.1–0.2 mm wide, at least distally. |
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45 Carex sparganioides |
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5 (1) |
Perigynium beak margins smooth. |
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(6) |
+ |
Perigynium beak margins serrulate. |
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(9) |
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6 (5) |
Pistillate scales not more than 1/3–3/4 length of perigynia; bases of perigynia not longitudinally striate on adaxial face. |
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41 Carex leavenworthii |
+ |
Pistillate scales at least 3/4 length of perigynia; bases of perigynia longitudinally striate on adaxial side. |
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(7) |
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7 (6) |
Perigynia ascending, 1.8–2.3 mm wide; pistillate scales 1.8–2.2 mm wide; achenes 1.6–2.7 mm. |
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27 Carex vallicola |
+ |
Perigynia spreading to reflexed when mature, 1–1.8 mm wide; pistillate scales 0.8–1.6 mm wide; achenes 1.3–1.6 mm. |
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(8) |
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8 (7) |
Perigynia (1.2–)1.4–1.8 mm wide, 1.5–2.3 times as long as wide; widest leaf blades 1.4–3 mm wide. |
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21 Carex retroflexa |
+ |
Perigynia 1–1.3 mm wide, 2.3–3.1 times as long as wide; widest leaf blades 1–1.7 mm wide. |
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22 Carex texensis |
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9 (5) |
Proximal bracts at least 2 times as long as inflorescences, 6 cm or longer; perigynia 1.9–3 mm wide. |
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(10) |
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Proximal bracts shorter than to less than 2 times as long as inflorescences, to 6(–11) cm; if longer, perigynia 0.7–1.8 mm wide. |
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(11) |
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10 (9) |
Proximal nodes of inflorescences as long as or longer than proximal spikes; perigynium beak 0.8–1.2 mm. |
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37 Carex arkansana |
+ |
Proximal nodes of inflorescences shorter than proximal spikes; perigynium beak (1–)1.4–1.8 mm. |
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38 Carex perdentata |
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11 (9) |
Inflorescences lax; proximal internodes more than 2 times as long as proximal spikes. |
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(12) |
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Inflorescences dense; proximal internodes less than 2 times as long as proximal spikes. |
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(17) |
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12 (11) |
Pistillate scales (2.5–)2.7–4.5 mm; perigynia not or only slightly spongy thickened at base, not longitudinally striate. |
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(13) |
+ |
Pistillate scales 1–2.5 mm; perigynia spongy thickened at base and longitudinally striate adaxially. |
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(14) |
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13 (12) |
Pistillate scales hyaline or pale brown, shorter than perigynia; perigynia 1.7–2.6 mm wide. |
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33 Carex divulsa |
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Pistillate scales brown, exceeding perigynia; perigynia 1.2–1.5 mm wide. |
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29 Carex hookeriana |
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14 (12) |
Stigmas straight, twisted or slightly coiled, 0.03–0.06 mm wide; spongy bases of perigynia 1–1.5 mm, 0.2–0.3 times length of perigynia. |
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(15) |
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Stigmas usually tightly coiled, 0.05–0.1 mm wide; spongy bases of perigynia 0.5–1.3 mm, not more than 0.2 times length of perigynia. |
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(16) |
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15 (14) |
Perigynia 1.5–3 times as long as wide; achenes 1–1.4 mm wide, not more than 2 times as long as wide. |
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23 Carex radiata |
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Perigynia 3–5 times as long as wide; achenes 0.8–1 mm wide, 2– 2.4 times as long as wide. |
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24 Carex socialis |
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16 (14) |
Widest leaf blades 1.8–2.6 mm wide; base of culms 1.5–2.2 mm wide. |
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25 Carex rosea |
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Widest leaf blades 0.9–1.5 mm at widest; base of culms 0.7–1.4 mm wide. |
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26 Carex appalachica |
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17 (11) |
Bodies of pistillate scales at least as long as and wide as perigynia, largely obscuring them. |
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(18) |
+ |
Bodies of pistillate scales shorter than perigynia and narrower; perigynia easily visible. |
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(22) |
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18 (17) |
Pistillate scales with awn to 1–4 mm. |
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(19) |
+ |
Pistillate scales acute or with awn to 1 mm. |
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(20) |
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19 (18) |
Perigynia 2.2–3 mm wide, distinctly veined abaxially; achenes 1.9–2.5 × 1.5–2 mm. |
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36 Carex austrina |
+ |
Perigynia 1.2–1.5 mm wide, veinless or obscurely veined abaxially; achenes 1.5–1.7 × 1.1–1.2 mm. |
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29 Carex hookeriana |
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20 (18) |
Inflorescences globose or ovoid heads, 0.8–2 cm × 6–15 mm; proximal spikes not distinct. |
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31 Carex hoodii |
+ |
Inflorescences oblong, 1.5–5 cm × 6–10 mm; proximal spikes ± distinct. |
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(21) |
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21 (20) |
Perigynia ascending to spreading; beak 0.6–1.3 mm; pistillate scales 3.4–4 × 1.6–2 mm; proximal bracts usually shorter than spikes. |
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28 Carex occidentalis |
+ |
Perigynia erect; beak 1.2–3 mm; pistillate scales 4–5.2 × 2–2.8 mm; proximal bracts longer than spikes, often longer than inflorescences. |
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30 Carex tumulicola |
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22 (17) |
Bodies of pistillate scales not more than 2/3 length of perigynia; inflorescences dense, spikes individually indistinct. |
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(23) |
+ |
Bodies of pistillate scales at least 2/3 length of perigynia; inflorescences dense or lax. |
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(24) |
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23 (22) |
Perigynium bodies elliptic to circular, widest point at 0.4–0.55 of length of body; beak 0.7–1.1 mm, apical teeth 0.3–0.5 mm. |
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40 Carex cephalophora |
+ |
Perigynium bodies ovate, widest point at 0.25–0.4 of length of body; beak 0.3– 0.8 mm, apical teeth 0.1–0.3 mm. |
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41 Carex leavenworthii |
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24 (22) |
Perigynium beak obscurely toothed at apex, apical teeth not more than 0.2 mm; widest leaf blades 2 mm wide. |
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27 Carex vallicola |
+ |
Perigynium beak distinctly toothed at apex, apical teeth mostly 0.2–0.7+ mm; widest leaf blades 2 mm wide. |
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(25) |
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25 (24) |
Ligules 4–8 mm, distinctly longer than wide; basal scales and sheaths frequently tinged red or purple. |
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32 Carex spicata |
+ |
Ligules not more than 4(–5) mm, as wide as or wider than long; basal scales and sheaths brown or black, without trace of red or purple. |
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(26) |
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26 (25) |
Pistillate scales, except for midvein, dark brown. |
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34 Carex muricata |
+ |
Pistillate scales, except for midvein, hyaline or brown brown. |
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(27) |
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27 (26) |
Inflorescences dense, globose to ovoid heads, 1–1.5 times as long as wide, spikes not distinct. |
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39 Carex mesochorea |
+ |
Inflorescences somewhat lax, oblong, (1.5–)2+ times as long as wide, proximal spikes ± distinct. |
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(28) |
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28 (27) |
Perigynium beak (1–)1.4–1.8 mm, apical teeth (0.5–)1.4–1.8 mm. |
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38 Carex perdentata |
+ |
Perigynium beak 0.2–1.5 mm, apical teeth 0.2–0.6 mm. |
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(29) |
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29 (28) |
Perigynia yellow-green, becoming dark brown and glossy when mature, veinless or weakly 7(–11)-veined abaxially. |
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34 Carex muricata |
+ |
Perigynia yellow or yellow-brown when mature, strongly 9–15-veined abaxially. |
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(30) |
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30 (29) |
Pistillate scales narrower than perigynia, not more than 2 mm wide, apex acute or with awn to 1.5(–2) mm. |
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35 Carex muehlenbergii |
+ |
Pistillate scales as wide as perigynia, widest 2+ mm wide, apex with awn to 1.5–4 mm. |
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36 Carex austrina |