Cyperus tetragonus |
Cyperus mutisii |
|
---|---|---|
fourangle flatsedge |
mutis' flatsedge |
|
Habit | Herbs, perennial, cespitose, rhizomatous. | Herbs, perennial, cespitose, rhizomatous. |
Culms | trigonous, (20–) 30–80 cm × 1–2.5 mm, glabrous or occasionally with scattered prickles on distal angles. |
trigonous, (20–)30–120 cm × 1.4–3.5 mm, glabrous or occasionally with scattered prickles on distal angles. |
Leaves | 9–11, flat to slightly V-shaped, 25–80 cm × 3.5–10 mm. |
2–4(–6), inversely W-shaped, 10–60(–70) cm × (2–)4–13 mm, margins and midribs scabridulous or glabrous. |
Inflorescences | spikes (1–)3–6, loosely cylindric or oblong with parallel sides, 1.5–4 cm × 10–17 mm; rays 6–12, 2–25 cm, glabrous or rarely scabridulous proximal to spikes; bracts 6–11, ascending at 45°, flat, (1–)10–20(–26) cm × 1–10 mm; rachilla deciduous, wings persistent, 0.4–0.5 mm wide. |
spikes (1–)3–6, narrowly cylindric, 1–4(–6) cm × 5–11 mm; rays 0 or 3–6, 2–23 cm; bracts 5–8, ascending at ± 45°, inversely W-shaped, (4–) 14–40(–46) cm × 1–12 mm; rachilla deciduous, wings persistent, 0.3–0.5 mm wide. |
Spikelets | 10–60, narrowly ellipsoid, quadrangular, 5–8 × 1.5–2 mm; floral scales persistent, (2–)3–7, appressed, clear at maturity, laterally reddish to purplish brown, medially greenish, often erose at maturity, laterally 3–5-ribbed, medially 3-ribbed, ovate-elliptic, 2.5–3.2 × 1.8–2.1 mm, apex obtuse. |
35–100, oblong-ellipsoid, ± terete, elliptic in cross section, 3–7 × (0.9–) 1.3–2 mm; distal spikelets spreading or ascending; floral scales persistent, 1–2(–5), appressed, becoming clear at maturity, laterally brownish to reddish brown, medially greenish, laterally 3–5-ribbed, medially 3-ribbed, often erose at maturity, ovate to elliptic, 2.2–3.2 × 1.5–2.1 mm, apex obtuse. |
Flowers | anthers 0.8–1 mm; styles 0.3–0.5 mm; stigmas 2–2.5 mm. |
anthers 0.6–0.8 mm; styles 0.4–0.8 mm; stigmas 1.2–2.2 mm. |
Achenes | brown to reddish brown, sessile, oblong-ovoid to broadly ellipsoid, slightly dorsiventrally flattened, 1.8–2 × 0.7–0.8 mm, apex obtuse, apiculate, surfaces papillose to puncticulate. |
brown to reddish brown, sessile, broadly ellipsoid, slightly dorsiventrally flattened, 1.5–1.8 × 0.7–0.9(–1) mm, apex obtuse, apiculate, surfaces papillose to puncticulate. |
Cyperus tetragonus |
Cyperus mutisii |
|
Phenology | Fruiting summer–fall (Jun–Nov). | Fruiting summer–fall (Jun–Nov). |
Habitat | Open woods, thickets, barrier islands | Clearings in montane forests, canyons |
Elevation | 0–1000 m (0–3300 ft) | 500–1500 m (1600–4900 ft) |
Distribution |
AL; AZ; FL; GA; MS; NC; NM
|
AZ; Mexico; Central America; South America |
Discussion | The status of Cyperus pringlei from the southwestern United States requires further study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus mutisii is recognized by its cylindric spikes borne digitately at the ends of the rays and its short, plump spikelets. As spikelets mature, the floral scales, having erose margins contrasting with the brownish sides, beome useful distinguishing features. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 189. | FNA vol. 23, p. 189. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. pringlei, C. tetragonus var. pringlei, Mariscus tetragonus | Mariscus mutisii, C. asper, C. compresso, C. ehrenbergianus, C. mutisii var. asper, C. mutisii var. contractus, C. mutisii var. semitribrachiatus, C. ochreatus, C. semitribrachiatus, Mariscus asper |
Name authority | Elliott: Sketch Bot. S. Carolina 1: 71. (1821) | (Kunth) Andersson: Galapagos Veg., 53. (1854) |
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