Cyperus plukenetii |
Cyperus amabilis |
|
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Plukenet's flatsedge, Plukenet's sedge |
foothill flatsedge |
|
Habit | Herbs, perennial, cespitose. | Herbs, annual, cespitose. |
Culms | basally cormlike, obtusely trigonous to subterete, 25–100 cm × 2–4 mm, densely minutely scabridulous. |
1–10(–25), roundly trigonous, 3–12 cm × 0.3–0.8 mm, glabrous. |
Leaves | inversely W-shaped, 20–70 cm × 4–7 mm, adaxial surface densely hirtellous. |
1–3–(4), 1–6 cm × 1(–1.5) 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. |
if rays absent heads single, dense, sessile, digitate, 5–20 × 10–30 mm, single heads 10–30(–50) mm; rays usually absent, if present 1–8 cm; 2d order rays infrequently present, 1–2 cm; bracts 3–6, erect to oblique, flat to V-shaped,(0.5–)2–10(–15) cm × 0.5–2 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. |
5–10(–20), linear to linear-lanceoloid, (5–)8–12(–35) × 1.6–2.3(–2.5) mm; floral scales (6–)16–30(–76), laterally glossy reddish brown to brown, medially greenish, sometimes also reddish or brownish, laterally ribless, medially strongly 3-ribbed, ovate-lanceolate, 1.9–2(–2.3) mm (including prominent excurved cusp of 0.3–0.5 mm) × 0.8–1.1 mm, apex truncate, emarginate, or cuspidate. |
Flowers | anthers 0.5–1 mm; styles 1.5–2 mm; stigmas 2 mm. |
stamens (1–)2–3; anthers ellipsoid, 0.3 mm, connectives not prolonged; styles 0.3–0.4 mm; stigmas 0.4–0.7 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. |
brown, slightly stipitate, obovoid to oblong, 0.8–0.9 × 0.4–0.5 mm, apex abruptly apiculate, surfaces papillose. |
Cyperus plukenetii |
Cyperus amabilis |
|
Phenology | Fruiting summer (Jul–Aug). | Fruiting summer. |
Habitat | Dry sand hills, xeric upland woods | Seasonally wet, sandy soils |
Elevation | 0–200 m (0–700 ft) | 500 m (1600 ft) |
Distribution |
AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
|
AZ; Mexico; Central America; South America; Asia; Africa |
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.) |
|
Source | FNA vol. 23, p. 180. | FNA vol. 23, p. 158. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycnostachys |
Sibling taxa | ||
Synonyms | C. amabilis var. macrostachyus, C. aurantiacus, C. aureus, C. aureus var. aurantiacus, C. aureus var. macrostachyus, C. aureus var. oligostachyus, C. microstachyus, C. oligostachyus | |
Name authority | Fernald: Rhodora 47: 110, plate 877. (1945) | Vahl: Enum. Pl. 2: 318. (1805) |
Web links |