Cyperus hermaphroditus |
Cyperus flavicomus |
|
---|---|---|
hermaphrodite flatsedge |
white-edge flatsedge |
|
Habit | Herbs, perennial, rhizomatous. | Herbs, annual, cespitose or single-stemmed. |
Culms | trigonous, (10–)30–80(–140) cm × (0.4–)1–3(–5) mm, glabrous. |
trigonous, easily compressed, 30–75 cm × 1–5 mm, basally soft, glabrous. |
Leaves | V-shaped or flanged V-shaped, (5–)15–70(–90) cm × (2–)4–10(–13) mm, glabrous. |
1–3, usually withered at anthesis, V-shaped, 5–35 cm × 2–8 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 loosely ovoid, 5–25 × 8–22 mm; rays (3–)5–11, 0.4–20 cm; 2d order rays occasionally present, 5–28 mm; bracts 3–7, horizontal to ascending at 30°, (2–)8–35 cm × (1–)4–10 mm. |
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. |
6–60, linear to lanceoloid, 7–30 × 2–3 mm, margins appearing serrate; floral scales 6–24, loosely overlapping, light brown to reddish brown, with conspicuous clear border, medially greenish, 5–7-ribbed, ovate-obovate, (1.4–)1.7–2.3 × 1.4–2 mm, apex acute to obtuse. |
Flowers | anthers (0.4–)0.6–1 mm; styles 0.4–1.6 mm; stigmas 1–1.5 mm. |
stamens 2–3; anthers 0.4 mm, connective apex reddish, to 0.1 mm; styles 0.1–0.3 mm; stigmas 0.7–1.5 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. |
jet black to dark reddish brown, sessile, obovoid, broadly rounded, 1.2–1.6 × 0.6–1.1 mm, surfaces minutely punctate. |
Cyperus hermaphroditus |
Cyperus flavicomus |
|
Phenology | Fruiting summer–fall. | Fruiting summer–early fall. |
Habitat | Arroyos | Emergent shorelines, roadsides ditches, marshes |
Elevation | 500–1200 m (1600–3900 ft) | 0–200 m (0–700 ft) |
Distribution |
AZ; TX; Mexico; South America; West Indies |
AL; AZ; FL; GA; KY; LA; MO; MS; NC; NM; PA; SC; TX; VA; Mexico; Central America; South America; Asia; Africa [Introduced in North America]
|
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.) |
Cyperus flavicomus has long been called C. albomarginatus (see G. C. Tucker 1994). The closely related (perhaps not distinct) C. macrostachyos Lamarck, a pantropical subspecies, has been reported from Central America; the relationship of the two species needs further study. Cyperus flavicomus has been introduced in New York; it has not persisted there (R. S. Mitchell and G. C. Tucker 1997). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 186. | FNA vol. 23, p. 159. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycreus |
Sibling taxa | ||
Synonyms | Carex hermaphrodita, Mariscus hermaphroditus, Mariscus jacquinii | C. albomarginatus, C. albomarginatus var. sabulosus, C. sabulosus, Pycreus albomarginatus, Pycreus sabulosus |
Name authority | (Jacquin) Standley: Contr. U.S. Natl. Herb. 18: 88. (1916) | Michaux: Fl. Bor.-Amer. 1: 27. (1803) |
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