Cyperus lanceolatus |
Cyperus lupulinus |
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epiphytic flatsedge |
Great Plains flatsedge, slender sand sedge |
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Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, bases cormose; rhizomes knotted, beaded. | ||||
Culms | trigonous, compressed, 15–75 cm × 0.5–3 mm, glabrous. |
trigonous, (3–)10–50 cm × 0.4–1.2 mm, glabrous. |
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Leaves | 1–3, 5–30 cm × 1–2 mm. |
flat, 5–40 cm × 1–3.5 mm. |
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Inflorescences | spikes 1(–2), ovoid, 5–23 × 9–21 mm; rays 2–3(–4), 0–15 mm; if rays absent, head single, compact, sessile, (12–)15–20 mm diam.; bracts 2–3, horizontal to vertical, 2–14 cm × 0.5–3.5 mm. |
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 | 1–6, oblong-lanceoloid, 5–26 × 2–3 mm; floral scales 12–54, closely imbricate, laterally yellowish brown, medially pale brown, occasionally greenish, laterally 1-ribbed, medially 3-ribbed, distinctly 2-keeled basally, ovate, 1.8–2.6 × 1.4–1.7 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 | stamens 2; anthers 0.4–0.5 mm, connectives not prolonged; styles 0.3–1 mm; stigmas 0.6–0.8(–1) mm. |
anthers 0.3–0.6 mm; styles 1 mm; stigmas 1–1.5 mm. |
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Achenes | brown, network of ridges forming isodiametric or square cells, stipitate, obovoid to ellipsoid, 1.1–1.3 × (0.5–)0.6 mm, apex acute to broadly rounded, surfaces minutely punctate or finely papillose. |
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 lanceolatus |
Cyperus lupulinus |
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Phenology | Fruiting summer. | |||||
Habitat | Marshes | |||||
Elevation | 0–100 m (0–300 ft) | |||||
Distribution |
AL; FL; GA; LA; TX; Mexico; Central America; South America; Africa
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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 | 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. 162. | FNA vol. 23, p. 176. | ||||
Parent taxa | Cyperaceae > Cyperus > subg. Pycreus | Cyperaceae > Cyperus > subg. Cyperus | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | C. densus, C. humboldtianus, C. lanceolatus var. compositus, Pycreus densus | Scirpus lupulinus | ||||
Name authority | Poiret: in J. Lamarck et al., Encycl. 7: 245. (1806) | (Sprengel) Marcks: Trans. Wisconsin Acad. Sci. 62: 271. (1974) | ||||
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