Cyperus plukenetii |
Cyperus aggregatus |
|
---|---|---|
Plukenet's flatsedge, Plukenet's sedge |
ballast sedge, inflated-scale flatsedge |
|
Habit | Herbs, perennial, cespitose. | Herbs, perennial, cespitose, rhizomatous. |
Culms | basally cormlike, obtusely trigonous to subterete, 25–100 cm × 2–4 mm, densely minutely scabridulous. |
trigonous, 20–100 cm × 0.8–2.5 mm, glabrous. |
Leaves | inversely W-shaped, 20–70 cm × 4–7 mm, adaxial surface densely hirtellous. |
5–10, V-shaped to flanged V-shaped, 10–70(–90) cm × 2–7 mm, margins and midribs scabridulous or glabrous. |
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 1(–6), densely cylindric, 6–30 × 5–11 mm; rays 3–12, 0.4–5(–7) cm; rays and rachis glabrous; usually only 1–2 spikes of inflorescence on elongate rays, other spikes sessile or nearly so; bracts 4–7, horizontal to slightly ascending, 1–16 cm × 0.5–4 mm; rachilla deciduous, wings persistent, 0.5 mm wide. |
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. |
20–80, ellipsoid, roughly quadrangular, 3–5 × 1–1.4 mm; floral scales 1–2(–4), appressed, stramineous to golden brown, often red-speckled, medially greenish, 9-ribbed, elliptic to ovate, 2.4–3.4 × 1.8–2.6 mm, apex obtuse. |
Flowers | anthers 0.5–1 mm; styles 1.5–2 mm; stigmas 2 mm. |
anthers 0.4–0.6 mm; styles 0.7–1.1 mm; stigmas 1.4–2.1 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. |
dark brown to reddish brown, sessile, broadly ellipsoid, 1.8–2.1 × 0.8–1 mm, apex apiculate, surfaces glabrous to finely puncticulate. |
Cyperus plukenetii |
Cyperus aggregatus |
|
Phenology | Fruiting summer (Jul–Aug). | Fruiting mid summer–fall (Jul–Oct). |
Habitat | Dry sand hills, xeric upland woods | Dry roadsides, pastures, thickets |
Elevation | 0–200 m (0–700 ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
|
AZ; LA; MS; NJ; NM; OR; PA; TX; Mexico; Central America; South America [Introduced, Australia]
|
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.) |
The records of Cyperus aggregatus in New Jersey, Oregon, and Pennsylvania represent introductions from ballast. The closely related Mexican and Central American Cyperus regiomontanus Britton has been collected once as an adventive or waif in southern California. It is distinguished from C. aggregatus by its silvery green, subulate-lanceolate spikelets and achenes that are only 0.4–0.6 mm wide. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 180. | FNA vol. 23. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | Mariscus aggregatus, C. cayennensis, C. flavus, C. flavus var. aggregatus, C. flavus var. laevis, Kyllinga cayennensis, Kyllinga squarrosa, Mariscus flavus, Mariscus laevis | |
Name authority | Fernald: Rhodora 47: 110, plate 877. (1945) | (Willdenow) Endlicher: Cat. Horti Vindob. 1: 93. (1842) |
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