Cyperus parishii |
Cyperus retroflexus |
|
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Parish flatsedge, Parish's flatsedge, Parish's nutgrass |
one-flower flatsedge |
|
Habit | Herbs, annual, cespitose. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, 5–25 cm × 1–1.5 mm, glabrous. |
trigonous, basally tuberous-thickened, (5–)15–40(–80) cm × 1–2.5 mm, glabrous. |
Leaves | flat to V-shaped, (5–)10–30(–60) cm × (0.5–)1–3(–4) mm. |
|
Inflorescences | spikes loosely ovoid, 15–25 mm wide; rays 1–6, 2–7 cm; bracts 2–5, 3–20 cm, ascending; rachilla deciduous, winged. |
spike 1, loosely to densely ovoid to cylindric, 8–36 × 8–20 mm; rays 3–6(–9), (5–)10–32 cm; bracts 3–6, horizontal to ascending at 30°, V-shaped, (1–)3–15(–30) cm × 0.5–4.5 mm; rachilla deciduous, wings 0.5–0.7 mm wide. |
Spikelets | 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. |
(5–)20–35(–65), linear to oblong (without narrowed basal portion), quadrangular; (2.2–)4–10(–18) × 0.7–1.1 mm; floral scales persistent, 1–5, appressed, pale greenish white laterally, stramineous with reddish dots, or deep red, greenish or light brown medially, 3–6-ribbed laterally, narrowly ovate to oblong-elliptic, 2.6–3.9 × 1.6–2 mm, apex rounded to ± acute, entire, mucronulate; distal scale with glabrous midrib and mucro 0.1–0.3(–0.5) mm; sterile terminal scale of spikelet only 0.4–0.6 mm wide, involute, frequently uncinate. |
Flowers | anthers 0.3–0.4 mm; styles 1 mm; stigmas 1.3–1.6 mm. |
anthers (0.3–)0.4–0.6 mm; styles 0.4–0.5 mm; stigmas 0.5–0.9 mm. |
Achenes | brown to dark purplish brown, broadly ellipsoid, 1–1.3 × 0.6–0.9 mm, surfaces puncticulate. |
light brown to reddish brown, sessile or slightly stipitate, ellipsoid, (1.8–)2–2.4 × 0.6–0.8(–0.9) mm, apex slightly apiculate, surfaces puncticulate. |
Cyperus parishii |
Cyperus retroflexus |
|
Phenology | Fruiting summer. | Fruiting mid summer–early fall (Jul–Sep). |
Habitat | Stream banks, desert washes, arroyos, roadsides | Damp, disturbed soils, croplands |
Elevation | 0 800 m (0 2600 ft) | 0–1000 m (0–3300 ft) |
Distribution |
AZ; CA; NM
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AL; AR; AZ; MO; MS; NM; OK; TX; Mexico
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Discussion | Cyperus retroflexus is distinguished from other species of Cyperus with deciduous spikelets by the involute, sterile terminal scale of the spikelet. In plants with cuspidate scales, the terminal scale is usually somewhat recurved, giving the appearance of a hook at the end of the spikelet. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 23, p. 170. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. congestus var. parishii | C. uniflorus var. floribundus, C. uniflorus var. retroflexus, Mariscus uniflorus |
Name authority | Britton ex Parish: Bull. S. Calif. Acad. Sci. 3: 52, plate 3. (1904) | Buckley: Proc. Acad. Nat. Sci. Philadelphia. 14: 9. (1862) |
Web links |