Cyperus echinatus |
Cyperus esculentus |
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globe flatsedge, teasel sedge |
nut flatsedge, nut grass, yellow nut sedge, yellow nut-grass |
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Habit | Herbs, perennial, single-stemmed to loosely cespitose. | Herbs, perennial, stoloniferous; stolons soft, spongy, flexible when dried, 2–8(–15) cm, bearing tubers (3–)6–11 mm diam. | ||||||||
Culms | basally cormlike, trigonous, (15–)30–100 cm × 0.5–3.5 mm, glabrous. |
trigonous, 15–60 (–100) cm × 0.6–3.4 mm, glabrous. |
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Leaves | flat to V-shaped, 10–65 cm × 3–9 mm, adaxial surface, margins minutely scabridulous. |
3–7, flat to V-shaped or flanged V-shaped, (6–)20–40(–80) cm × 2–4 (–6.5) mm. |
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Inflorescences | spikes densely globose to globose-ovoid, 8–17 mm wide; rays 3–12, 2–12 cm, scaberous adaxially especially distally; rachis 4–8 mm; bracts (3–)4–7, ascending at 30(–45)°, flat, 5–35 cm × 2–9 mm; rachilla persistent, wings 0.5–0.7 mm wide. |
spikes broadly ellipsoid to ovoid or hemispheric, (12–)18–30 × (12–)18–35 mm; rachis 4–17 mm; rays 4–10, (0.3–)2–12 cm; bracts (3–)4–5(–7), ± horizontal to ascending at 45(–75)°, V-shaped to flanged V-shaped, (1.5–)5–30 cm × 0.5–4 mm; rachilla persistent, wings hyaline, 0.3–0.5 mm wide. |
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Spikelets | 50–100, oblong-lanceoloid, ± terete-quadrangular, (3.5–)4–7 × 1–1.4 mm; distal spikelet spreading or ascending; floral scales persistent, 3–5, appressed, stramineous to brownish, 4-ribbed laterally, oblong-elliptic, 3.5–4.5 × 1–1.8 mm, membranous, apex entire or emarginate with mucro to 0.3 mm. |
(3–)10–20(–28), divaricate or ascending, yellowish brown to dark brown, linear to linear-lanceoloid, compressed-quadrangular, (5–)10–20(–55) × (1.2–)1.4–2(–3) mm; floral scales persistent, 6–34, spreading or appressed, ovate-lanceolate, laterally 7–9-ribbed, laterally yellowish brown to dark brown medially brownish, reddish, or greenish, ovate, or ovate-deltate, medially 3-ribbed, 1.8–2.7(–3.4) × (1–)1.5–1.8(–2.4) mm, apex acute or subacute. |
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Flowers | anthers 0.4–0.8 mm; styles 0.5–0.6 mm; stigmas 1 mm. |
anthers (1–)1.2–1.5(–2.1) mm; styles (0.7–)1–1.2(–2.2) mm; stigmas (1.2–)1.8–2.3(–4) mm. |
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Achenes | brown, ± stipitate, oblong, (1.5–)1.8–2.3 × 0.5–0.6(–0.7) mm (1/2 length of floral scales), apex obtuse, surfaces puncticulate. |
(seldom maturing) brown, sessile, ellipsoid, (1.1–)1.3–1.5(–1.6) × 0.3–0.6(–0.8) mm, apex obtuse, surfaces puncticulate. |
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Cyperus echinatus |
Cyperus esculentus |
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Phenology | Fruiting summer–early fall. | |||||||||
Habitat | Disturbed, sunny sites, in mesic places, well-drained soils | |||||||||
Elevation | 0–500 m (0–1600 ft) | |||||||||
Distribution |
AL; AR; DC; DE; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WI; WV; West Indies
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AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; BC; NB; ON; QC; nearly worldwide
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Discussion | The records for Rhode Island and Wisconsin are according to M. L. Horvat (1941); we have not seen specimens from those states. Cyperus echinatus is usually recognized by its tight, nearly spheric spikes; it may occasionally be hard to distinguish from C. croceus and C. retrorsus. Compared to C. retrorsus, C. echinatus has larger spikelets and longer floral scales, anthers, and achenes. In contrast to C. echinatus, C. croceus has looser spikes, shorter, broader, greenish or yellowish floral scales, shorter, more ovoid achenes, and shorter anthers. Furthermore, C. echinatus is predominantly an inland species of roadsides, pastures, and other disturbed ground; C. retrorsus is primarily a coastal species and occurs in drier, sandier sites. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Varieties 4 (3 in the flora). Cyperus esculentus is a widespread and polymorphic species. Although seven varieties have been recognized (G. Kükenthal (1935–1936), recent studies based primarily on spikelet features provided support for four varieties (P. Schippers et al. 1995). Cyperus esculentus var. esculentus is restricted to the Old World. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 23, p. 182. | FNA vol. 23. | ||||||||
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus | ||||||||
Sibling taxa | ||||||||||
Subordinate taxa | ||||||||||
Synonyms | Scirpus echinatus, C. ovularis, C. ovularis var. americanus, C. ovularis var. sphaericus, C. ovularis var. wolfii, C. wolfii, Kyllinga ovularis, Mariscus ovularis | |||||||||
Name authority | (Linnaeus) Alph. Wood: Class-book Bot. ed. s.n.(b), 734. (1861) | Linnaeus: Sp. Pl. 1: 45. (1753) | ||||||||
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