Cyperus echinatus |
Cyperus refractus |
|
---|---|---|
globe flatsedge, teasel sedge |
reflexed flatsedge |
|
Habit | Herbs, perennial, single-stemmed to loosely cespitose. | Herbs, perennial, cespitose, with inconspicuous, short rhizomes scarcely visible between culm bases. |
Culms | basally cormlike, trigonous, (15–)30–100 cm × 0.5–3.5 mm, glabrous. |
basally cormlike, trigonous, 30–100 cm × 2–4 mm, glabrous. |
Leaves | flat to V-shaped, 10–65 cm × 3–9 mm, adaxial surface, margins minutely scabridulous. |
V-shaped to flat, 20–70 cm × 3–8 mm, adaxial surface, margins minutely scabridulous. |
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 loose, broadly ellipsoid to ovoid, 4–7 × 2–6 cm; rays 6–13(–16), 4–25 cm, glabrous; rachis 1.5–3 cm; bracts 3–6, horizontal to ascending at 30°, flat, 5–35 cm × 2.5–6 mm; rachilla persistent, wings 0.4–0.5 mm wide. |
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. |
(13–)20–60(–74), linear, ± terete, (11–)13–25(–28) × 1.2–1.5 mm; distal spikelets spreading or ascending; floral scales persistent, (2–)3–6, stramineous, red-purple striate, laterally 3–5-ribbed, ovate-lanceolate, 4.5–5.3 × 1.2–1.5 mm. |
Flowers | anthers 0.4–0.8 mm; styles 0.5–0.6 mm; stigmas 1 mm. |
anthers 1–1.5 mm; styles 1.5 mm; stigmas 1.5 mm. |
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. |
brown to purplish brown, oblong-linear (5–6 times long as wide), 2.6–3 × 0.5–0.6 mm, base cuneate, apex obtuse, surfaces puncticulate. |
Cyperus echinatus |
Cyperus refractus |
|
Phenology | Fruiting summer–early fall. | Fruiting summer (Jul–Aug). |
Habitat | Disturbed, sunny sites, in mesic places, well-drained soils | Sandy riverbanks, gravelly roadsides, pastures, disturbed places |
Elevation | 0–500 m (0–1600 ft) | 20–300 m (100–1000 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
|
AL; AR; DC; GA; MD; MO; NC; PA; SC; TN; VA; WV |
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.) |
Cyperus refractus is often mistaken for C. strigosus, which has shorter anthers (0.4–0.5 mm) and spreading, ± deciduous floral scales. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 182. | FNA vol. 23, p. 182. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Cyperus |
Sibling 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) | Engelmann ex Boeckeler: Linnaea 36: 369. 1870, based on Cyperus refrofractus Engelmann ex Steudel, Syn. Pl. Glumac. 2: 47. 1855, not (Linnaeus) Torrey (1848) |
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