Cyperus hermaphroditus |
Cyperus lupulinus |
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hermaphrodite flatsedge |
Great Plains flatsedge, slender sand sedge |
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Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, cespitose, bases cormose; rhizomes knotted, beaded. | ||||
Culms | trigonous, (10–)30–80(–140) cm × (0.4–)1–3(–5) mm, glabrous. |
trigonous, (3–)10–50 cm × 0.4–1.2 mm, glabrous. |
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Leaves | V-shaped or flanged V-shaped, (5–)15–70(–90) cm × (2–)4–10(–13) mm, glabrous. |
flat, 5–40 cm × 1–3.5 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 rather densely ovoid to globose, 1.2–3.5 cm; rays 0 or 1–4, 1–6 cm; rachis 1–3.5 mm; bracts 2–4, horizontal to reflexed, flat, 6–25 cm; rachilla ± deciduous, wingless. |
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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. |
15–60, compressed, oblong-lanceoloid, (3–)6–22 × 2.5–4 mm; floral scales deciduous, 5–22, off-white to light reddish brown, laterally 3–5-ribbed, ovate-elliptic, 2.5–4 × 2–2.6 mm, margins loosely spreading or clasping achene, apex entire to mucronate, mucro 0.05–0.2 mm. |
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Flowers | anthers (0.4–)0.6–1 mm; styles 0.4–1.6 mm; stigmas 1–1.5 mm. |
anthers 0.3–0.6 mm; styles 1 mm; stigmas 1–1.5 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. |
dark brown or black, sessile, oblong-ellipsoid to ellipsoid, 1.7–2.2 × 0.8–1.2 mm, apex obtuse, apiculate, surfaces puncticulate. |
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2n | = 166. |
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Cyperus hermaphroditus |
Cyperus lupulinus |
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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 |
AR; CO; CT; DC; DE; GA; IA; ID; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; NC; NE; NH; NJ; NY; OH; OR; PA; RI; TN; TX; VA; VT; WI; WV; NB; NS; ON; QC
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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.) |
Subspecies 2 (2 in the flora). Cyperus lupulinus was studied in detail (B. G. Marcks 1974). Ranges of the two subspecies overlap somewhat. Cyperus lupulinus subsp. lupulinus is found chiefly in the Great Plains, and subsp. macilentus is centered in the Northeast. It is seldom difficult to assign specimens to subspecies. The hybrid of Cyperus lupulinus with C. schweinitzii is C. ×mesochorus Geise. It is occasionally encountered with the two parent species in the north-central states (Illinois, Indiana, Michigan, Minnesota, and Wisconsin) and has been recorded once from Quebec. The hybrid is similar in size to C. schweinitzii; it has fewer rays, inflorescence bracts 30–45º above horizontal, and floral scales with mucros 0.4–0.5 mm. (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, p. 176. | ||||
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Carex hermaphrodita, Mariscus hermaphroditus, Mariscus jacquinii | Scirpus lupulinus | ||||
Name authority | (Jacquin) Standley: Contr. U.S. Natl. Herb. 18: 88. (1916) | (Sprengel) Marcks: Trans. Wisconsin Acad. Sci. 62: 271. (1974) | ||||
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