Cyperus hermaphroditus |
Cyperus esculentus |
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hermaphrodite flatsedge |
nut flatsedge, nut grass, yellow nut sedge, yellow nut-grass |
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Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, stoloniferous; stolons soft, spongy, flexible when dried, 2–8(–15) cm, bearing tubers (3–)6–11 mm diam. | ||||||||
Culms | trigonous, (10–)30–80(–140) cm × (0.4–)1–3(–5) mm, glabrous. |
trigonous, 15–60 (–100) cm × 0.6–3.4 mm, glabrous. |
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Leaves | V-shaped or flanged V-shaped, (5–)15–70(–90) cm × (2–)4–10(–13) mm, glabrous. |
3–7, flat to V-shaped or flanged V-shaped, (6–)20–40(–80) cm × 2–4 (–6.5) mm. |
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Inflorescences | spikes 1(–5), rather densely ovoid or oblong-cylindric, (10–)25–45(–62) × 7–22 mm, 11–21 spikelets per 5 mm of rachis; rays (3–)5–10(–17), (1–)5–12(–24) cm; bracts (2–)4–8, ascending at 30–45°, V- or inversely W-shaped, (2–)8–40(–65) cm × (1–)2–8 mm; rachilla deciduous, wings 0.4–0.5 mm wide. |
spikes broadly ellipsoid to ovoid or hemispheric, (12–)18–30 × (12–)18–35 mm; rachis 4–17 mm; rays 4–10, (0.3–)2–12 cm; bracts (3–)4–5(–7), ± horizontal to ascending at 45(–75)°, V-shaped to flanged V-shaped, (1.5–)5–30 cm × 0.5–4 mm; rachilla persistent, wings hyaline, 0.3–0.5 mm wide. |
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Spikelets | (10–)50–150, oblong to linear, quadrangular, (3–)4–8(–18) × (0.8–)1–1.2(–1.6) mm; distal spikelet spreading or ascending; floral scales (1–) 3–8, pale greenish white to golden brown, deep brown, or reddish brown, medially usually green, weakly to strongly 3(–4)-ribbed laterally, 1–3-ribbed medially, ovate to elliptic, (2–)2.6–3.2(–4) × 1.2–2 mm, apex obtuse. |
(3–)10–20(–28), divaricate or ascending, yellowish brown to dark brown, linear to linear-lanceoloid, compressed-quadrangular, (5–)10–20(–55) × (1.2–)1.4–2(–3) mm; floral scales persistent, 6–34, spreading or appressed, ovate-lanceolate, laterally 7–9-ribbed, laterally yellowish brown to dark brown medially brownish, reddish, or greenish, ovate, or ovate-deltate, medially 3-ribbed, 1.8–2.7(–3.4) × (1–)1.5–1.8(–2.4) mm, apex acute or subacute. |
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Flowers | anthers (0.4–)0.6–1 mm; styles 0.4–1.6 mm; stigmas 1–1.5 mm. |
anthers (1–)1.2–1.5(–2.1) mm; styles (0.7–)1–1.2(–2.2) mm; stigmas (1.2–)1.8–2.3(–4) mm. |
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Achenes | brown or reddish brown, sessile or nearly so, ellipsoid, 1.4–1.8(–2) × 0.6–0.8(–1) mm, apex acute to obtuse, slightly apiculate, surfaces puncticulate. |
(seldom maturing) brown, sessile, ellipsoid, (1.1–)1.3–1.5(–1.6) × 0.3–0.6(–0.8) mm, apex obtuse, surfaces puncticulate. |
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Cyperus hermaphroditus |
Cyperus esculentus |
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Phenology | Fruiting summer–fall. | |||||||||
Habitat | Arroyos | |||||||||
Elevation | 500–1200 m (1600–3900 ft) | |||||||||
Distribution |
AZ; TX; Mexico; South America; West Indies |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; BC; NB; ON; QC; nearly worldwide
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Discussion | An erroneous report of Cyperus hermaphroditus from Alabama was based on misidentification of C. thyrsiflorus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 4 (3 in the flora). Cyperus esculentus is a widespread and polymorphic species. Although seven varieties have been recognized (G. Kükenthal (1935–1936), recent studies based primarily on spikelet features provided support for four varieties (P. Schippers et al. 1995). Cyperus esculentus var. esculentus is restricted to the Old World. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 23, p. 186. | FNA vol. 23. | ||||||||
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Carex hermaphrodita, Mariscus hermaphroditus, Mariscus jacquinii | |||||||||
Name authority | (Jacquin) Standley: Contr. U.S. Natl. Herb. 18: 88. (1916) | Linnaeus: Sp. Pl. 1: 45. (1753) | ||||||||
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