Cyperus hermaphroditus |
Cyperus houghtonii |
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hermaphrodite flatsedge |
Houghton's flatsedge |
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Habit | Herbs, perennial, rhizomatous. | Herbs, perennial, cespitose, bases cormose, rhizomatous. |
Culms | trigonous, (10–)30–80(–140) cm × (0.4–)1–3(–5) mm, glabrous. |
trigonous, 5–50 cm × 0.5–1.5 mm, glabrous. |
Leaves | V-shaped or flanged V-shaped, (5–)15–70(–90) cm × (2–)4–10(–13) mm, glabrous. |
V-shaped, 12–30 cm × 1–6 mm. |
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 ± globose to broadly ovoid, 8–20 mm wide; rays 1–8 cm; rachis 2–5 mm, glabrous; bracts 3–8, weakly ascending, flat, 3–20 cm × 1–3.5 mm; rachilla deciduous, wingless. |
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. |
3–18, compressed, ovoid to oblong-lanceoloid, 4–15 × 2.6–3.4 mm; floral scales deciduous, 3–18, laterally stramineous to reddish brown, laterally 3–4-ribbed, broadly ovate, 1.8–2.5 × 1.3–1.6 mm, apex with mucro 0.1–0.2 mm. |
Flowers | anthers (0.4–)0.6–1 mm; styles 0.4–1.6 mm; stigmas 1–1.5 mm. |
anthers 0.5–0.7 mm; styles 0.4–0.6 mm; stigmas 1–1.5 mm. |
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, sessile, broadly ellipsoid, 1.5–2 × 1–1.5 mm, apex obtuse, apiculate, surface glabrous, puncticulate, or papillose. |
2n | = 168, 170, 172. |
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Cyperus hermaphroditus |
Cyperus houghtonii |
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Phenology | Fruiting summer–fall. | Fruiting summer. |
Habitat | Arroyos | Riverbanks, sand bars, lakeshores, sand dunes, sandy openings in woods, especially among Jack pines |
Elevation | 500–1200 m (1600–3900 ft) | 0–1100 m (0–3600 ft) |
Distribution |
AZ; TX; Mexico; South America; West Indies |
IL; IN; MA; MD; ME; MI; MN; NH; NJ; NY; OH; PA; VA; VT; WI; WV; MB; 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.) |
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Source | FNA vol. 23, p. 186. | FNA vol. 23, p. 175. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | Carex hermaphrodita, Mariscus hermaphroditus, Mariscus jacquinii | |
Name authority | (Jacquin) Standley: Contr. U.S. Natl. Herb. 18: 88. (1916) | Torrey: Ann. Lyceum Nat. Hist. New York 3: 277. (1836) |
Web links |