Cyperus digitatus |
Cyperus squarrosus |
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finger flatsedge |
awn cyperus, awn flatsedge, bearded flatsedge |
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Habit | Herbs, perennial, rhizomatous, coarse. | Herbs, annual, cespitose, with fibrous roots. |
Culms | trigonous, 50–150 cm × 2–15 mm, glabrous (rarely sparsely scabridulous on angles proximal to bracts). |
1–20, trigonous, 2–16 cm × 0.5–0.8 mm, glabrous. |
Leaves | inversely W-shaped, 40–100 cm × 5–15 mm. |
1–3, flat to V-shaped, (1–)5–10(–15) × 0.5–2.5 mm. |
Inflorescences | spikes 1–4, cylindric, (2.5–)3.5–5 × 1.2–1.5 cm; rays 8–10, (1–)15–35 cm; 2d order rays 1–3 cm; bracts 8–12, ascending at 45–60°, (5–)20–80 cm × 3–15 mm; 2d order bracts 3–7 cm × 2–4 mm; rachilla persistent, wings 0.3 mm wide, at achene maturation adaxial edge of wing detaching from rachilla, base remaining firmly attached. |
spike 1, loosely to densely ovoid to oblong, 6–20(–40) × 9–15(–20) mm; rays absent or 1–3(–6), 4–40 mm; bracts (1–)2–4, longest ± erect, V-shaped, 1–15 cm × 0.5–3 mm; rachilla ± deciduous, wingless. |
Spikelets | 35–65, slightly compressed, linear, ± quadrangular, 5–8 × 0.8–1.1 mm; floral scales deciduous, 12–16, appressed, marginally clear, laterally reddish along midrib, medially green, laterally 1–2-ribbed, medially strongly 5-ribbed, ovate, 1.6–1.8 × 1.1–1.3 mm, apex mucronulate. |
(2–)6–20(–40), greenish to reddish brown, somewhat compressed, ovoid-lanceoloid to oblong, 2.5–10(–20) × 1.3–2.2 mm (excluding awns); floral scales deciduous, (4–)10–20(–34), greenish to stramineous or brownish red laterally, greenish medially, (5–)7–9(–11)-ribbed nearly to margins, oblong-lanceolate, (1.2–)1.3–1.8(–2.2) × (0.5–)0.7–0.8(–1) mm, apex cuspidate, excurved awn additional 0.5–1(–1.3) mm. |
Flowers | anthers 0.4–0.5 mm, connective blunt, at most 0.1 mm; styles 0.8–1 mm; stigmas 0.4 mm. |
stamen 1, filaments 1.5 mm; anthers oblong, 0.2–0.3 mm, connective apex reddish, minute; styles 0.3–0.5 mm; stigmas 0.4–0.7 mm. |
Achenes | brown or whitish, sessile, ellipsoid, slightly wider at base, 0.9 × 0.4 mm, surfaces finely puncticulate. |
light brown to nearly black, stipitate, obovoid (occasionally linear-spatulate or linear oblong, infrequently constricted in middle), 0.7–0.8(–1.1) × (0.2–)0.3–0.4(–0.5) mm, stipe 0.05–0.1 × 0.1 mm, apex truncate, apiculate, surfaces papillose. |
Cyperus digitatus |
Cyperus squarrosus |
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Phenology | Fruiting summer. | Fruiting summer. |
Habitat | Wet pastures, stream banks | Moist, disturbed soils, gravelly roadsides, flood plains, edges of puddles, muddy places |
Elevation | 0–100 m (0–300 ft) | 0–2500 m (0–8200 ft) |
Distribution |
FL; TX; Mexico; Central America; South America; Asia; Africa |
AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; ON; QC; Mexico; Central America; South America; West Indies; Bermuda; Eurasia; Africa; Atlantic Islands; Indian Ocean Islands; Pacific Islands; Australia
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Discussion | Cyperus squarrosus can be recognized by its small size and annual habit combined with its oblong-lanceolate floral scales bearing five to eleven conspicuous ribs and excurved awns. Some collections have been misidentified as C. acuminatus, an annual species of subg. Pycnostachys that has ovate-lanceolate, three-ribbed floral scales and digitately clustered spikelets. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 173. | FNA vol. 23, p. 165. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Chlorocyperus inflexus, C. aristatus, C. aristatus var. inflexus, C. aristatus var. runyonii, C. inflexus, Dichostylis aristata, Mariscus squarrosus | |
Name authority | Roxburgh: Fl. Ind. 1: 209. (1820) | Linnaeus: Cent. Pl. II, 6. (1756) |
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