Cyperus plukenetii |
Cyperus flavicomus |
|
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Plukenet's flatsedge, Plukenet's sedge |
white-edge flatsedge |
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Habit | Herbs, perennial, cespitose. | Herbs, annual, cespitose or single-stemmed. |
Culms | basally cormlike, obtusely trigonous to subterete, 25–100 cm × 2–4 mm, densely minutely scabridulous. |
trigonous, easily compressed, 30–75 cm × 1–5 mm, basally soft, glabrous. |
Leaves | inversely W-shaped, 20–70 cm × 4–7 mm, adaxial surface densely hirtellous. |
1–3, usually withered at anthesis, V-shaped, 5–35 cm × 2–8 mm. |
Inflorescences | spikes turbinate, 10–12 × 6–9 mm, ± as long as wide; rays 6–12, 1–30 cm (longest bract equaling or shorter than longest ray), harshly scabrid; bracts 3–10, horizontal to ascending at 30°, inversely W-shaped, 6–27 cm × 3–6 mm; rachilla persistent, wings hyaline, 0.5 mm wide, covering 1/2 of mature achene. |
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 | 30–60, proximal spikelets reflexed nearly parallel to ray, distal ones spreading, linear, ± terete, 6–8 × 1–1.4 mm; floral scales persistent, 1(–2), appressed, stramineous, often suffused with reddish purple, laterally 4–6-ribbed, ovate-lanceolate, 4–4.5 × 1.4–1.6 mm, apex straight, excurved mucronate or cuspidate; terminal scale spinose. |
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 0.5–1 mm; styles 1.5–2 mm; stigmas 2 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 | dark brown, narrowly oblong, (2.4–)2.7–2.9(–3.2) × 0.7–0.8 mm, base cuneate, apex obtuse, 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 plukenetii |
Cyperus flavicomus |
|
Phenology | Fruiting summer (Jul–Aug). | Fruiting summer–early fall. |
Habitat | Dry sand hills, xeric upland woods | Emergent shorelines, roadsides ditches, marshes |
Elevation | 0–200 m (0–700 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
|
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]
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Discussion | Cyperus plukenetii is distinguished by its tight, burlike spikes, few-flowered spikelets, and densely pubescent culms, leaves, and rays. (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. 180. | FNA vol. 23, p. 159. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycreus |
Sibling taxa | ||
Synonyms | C. albomarginatus, C. albomarginatus var. sabulosus, C. sabulosus, Pycreus albomarginatus, Pycreus sabulosus | |
Name authority | Fernald: Rhodora 47: 110, plate 877. (1945) | Michaux: Fl. Bor.-Amer. 1: 27. (1803) |
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