Cyperus prolixus |
Cyperus parishii |
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mosquito flatsedge |
Parish flatsedge, Parish's flatsedge, Parish's nutgrass |
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Habit | Herbs, perennial; rhizomes 3–20 cm × 1–2 cm, indurate. | Herbs, annual, cespitose. |
Culms | stoutly trigonous, thickened, 50–300 cm × 5–30 mm, basally indurate, glabrous. |
trigonous, 5–25 cm × 1–1.5 mm, glabrous. |
Leaves | V-shaped, with cross ribs, 40–130 cm × 10–15 mm, margins and keel scabrid. |
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Inflorescences | spikes appressed-ascending, narrowly cylindric, (2–)3–45 mm × (4–)7–10 mm; rays (5–)9–12, 2–22(–30) cm; 2d order rays distinctly flattened, 1–10 cm; 3d order rays flattened, 0.5–3 cm; rachis 2.5–4 cm; bracts (6–)9–10, ascending at 45–75°, V- or inversely W-shaped, (5–)15–90 cm × 0.5–20 mm; rachilla persistent, wings 0.2–0.4 mm wide. |
spikes loosely ovoid, 15–25 mm wide; rays 1–6, 2–7 cm; bracts 2–5, 3–20 cm, ascending; rachilla deciduous, winged. |
Spikelets | (4–)10–35, appressed-ascending, compressed, linear, 7–12(–15) × 0.6–1.2 mm; floral scales deciduous, 6–20, marginally clear, laterally brown, medially green, laterally 2–3-ribbed, medially 1-ribbed, oblong-ovate, (3.2–) 3.8–4.3 × 1.2–1.7 mm, apex spreading, acute to obtuse, mucronulate. |
5–30, linear, flattened, 6–22 × 1.5–2.2 mm; floral scales ± deciduous, (4–)8–12, red, reddish purple, or reddish brown, medially green, elliptic, laterally 2–4-ribbed, 2.3–3.1 × 1.2–2 mm, apex acute to obtuse. |
Flowers | anthers 0.7–0.9 mm, connective apex bright red, oblong, to 0.1 mm; styles 0.8–1.3 mm; stigmas 2–3.3 mm. |
anthers 0.3–0.4 mm; styles 1 mm; stigmas 1.3–1.6 mm. |
Achenes | brown, sessile, narrowly ellipsoid, 1.8–2.5 × 0.8–1.3 mm, apex ± acute, not apiculate, surfaces puncticulate. |
brown to dark purplish brown, broadly ellipsoid, 1–1.3 × 0.6–0.9 mm, surfaces puncticulate. |
Cyperus prolixus |
Cyperus parishii |
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Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Coastal marshes | Stream banks, desert washes, arroyos, roadsides |
Elevation | 0–10 m [0–30 ft] | 0 800 m [0 2600 ft] |
Distribution |
LA; Mexico; Central America; South America |
AZ; CA; NM
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Discussion | Cyperus prolixus produces large plants, similar in habit to C. giganteus and C. papyrus but easily distinguished by flattened rays. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 167. | FNA vol. 23, p. 170. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. amplissimus | C. congestus var. parishii |
Name authority | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 206. (1816) | Britton ex Parish: Bull. S. Calif. Acad. Sci. 3: 52, plate 3. (1904) |
Web links |