Cyperus prolixus |
Cyperus sanguinolentus |
|
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mosquito flatsedge |
purpleglume flatsedge |
|
Habit | Herbs, perennial; rhizomes 3–20 cm × 1–2 cm, indurate. | Herbs, perennial; rhizomes ± horizontal, to 12 cm × 0.8–1.2 mm. |
Culms | stoutly trigonous, thickened, 50–300 cm × 5–30 mm, basally indurate, glabrous. |
± terete to roundly trigonous, 3–25(–60) cm × 0.3–2 mm, glabrous. |
Leaves | V-shaped, with cross ribs, 40–130 cm × 10–15 mm, margins and keel scabrid. |
1–3, V-shaped, 1–8(–15) cm × 1–2 mm. |
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. |
spike 1, loosely ovoid, 7–14 × 8–20 mm; rays (0–)1–4, to 2(–3) cm; bracts 2–4, horizontal to ascending at 30(–45)°, V-shaped to flat, 1–8(–18) cm × 0.5–1.5(–2) mm. |
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. |
3–5(–14), oblong to linear-lanceoloid, 8–18 × 2–2.6(–3) mm; floral scales (6–)10–26(–32), laterally clear to light brown, sometimes with purplish margins, medially light brown, 2-keeled, laterally ribless, medially 2–3-ribbed, oblong to ovate, 1.9–2.2(–2.7) × 1.8–2.3 mm, apex 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. |
stamens 3; anthers ellipsoid, 0.3–0.6 mm, connective not prolonged; styles 0.6–1 mm; stigmas 1–1.5 mm. |
Achenes | brown, sessile, narrowly ellipsoid, 1.8–2.5 × 0.8–1.3 mm, apex ± acute, not apiculate, surfaces puncticulate. |
brown, ± stipitate, obovoid to ovoid, 1–1.4 × 0.6–0.8 mm, apex truncate, apiculate, surfaces minutely punctate. |
Cyperus prolixus |
Cyperus sanguinolentus |
|
Phenology | Fruiting summer. | Fruiting late summer–fall. |
Habitat | Coastal marshes | Emergent shorelines, ditches |
Elevation | 0–10 m [0–30 ft] | 20 m [70 ft] |
Distribution |
LA; Mexico; Central America; South America |
AL; GA; LA; MS; Asia; Africa [Introduced in North America] |
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.) |
Cyperus sanguinolentus is the only rhizomatous, distigmatic Cyperus in the eastern United States. An early collection from Louisiana was described as C. louisianensis, supposedly endemic. Recent field work and morphometric studies convincingly showed it to be an introduction of the Asian C. sanguinolentus) (J. R. Carter and C. T. Bryson 2001. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 167. | FNA vol. 23, p. 161. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | C. amplissimus | C. louisianensis, Pycreus sanguinolentus |
Name authority | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 206. (1816) | Vahl: Enum. Pl. 2: 351. (1805) |
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