Cyperus echinatus |
Cyperus ochraceus |
|
---|---|---|
globe flatsedge, teasel sedge |
pond flatsedge |
|
Habit | Herbs, perennial, single-stemmed to loosely cespitose. | Herbs, perennial, cespitose; rhizomes oblique. |
Culms | basally cormlike, trigonous, (15–)30–100 cm × 0.5–3.5 mm, glabrous. |
roundly trigonous, 20–50(–80) cm × 1–3 mm, glabrous. |
Leaves | flat to V-shaped, 10–65 cm × 3–9 mm, adaxial surface, margins minutely scabridulous. |
3–11, V-shaped, 12–40 cm. |
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. |
heads loosely to rather densely hemispheric, 15–30 mm diam.; rays 5–10, 2–12 cm; 2d order rays occasionally produced, 5–25 mm; bracts 4–8, approximately horizontal to ascending at 30°, V-shaped, 10–36 cm × 1.5–4 mm, margins glabrous. |
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. |
(4–)10–30, greenish, grayish, or stramineous, oblong to linear-oblong, compressed, (5–)7–10(–35) × 2–3 mm; floral scales 10–25(–85), laterally yellowish brown, medially yellowish or brownish, laterally ribless, medially 2-ribbed with groove between ribs, broadly ovate (widest in proximal 1/2), (1.2–)1.5–2 × 1.2–2 mm, apex obtuse (declined (45–)60–90º from rachilla). |
Flowers | anthers 0.4–0.8 mm; styles 0.5–0.6 mm; stigmas 1 mm. |
stamen 1; anthers oblong, 0.8–1.2 mm, connective not prolonged; styles basally thickened, confluent with summit of achene, 0.6–1.2 mm; stigmas 0.3–0.6 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. |
reddish brown to dark purplish brown, dull or more often iridescent, stipitate, broadly ellipsoid, 1–1.5 mm × 0.4–0.6(–0.7) mm, base cuneate to ± attenuate, stipe 0.1–0.2 mm, apex acute, beak 0.1–0.5 mm, surfaces reticulate with network of low ridges. |
Cyperus echinatus |
Cyperus ochraceus |
|
Phenology | Fruiting summer–early fall. | Fruiting summer. |
Habitat | Disturbed, sunny sites, in mesic places, well-drained soils | Damp, disturbed soils, ditches, marshes |
Elevation | 0–500 m (0–1600 ft) | 0–200 m (0–700 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
|
FL; GA; LA; MS; PA; TX; Mexico; Central America; South America
|
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.) |
In Pennsylvania, Cyperus ochraceus has been recorded in areas where ballast has been discarded. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23, p. 182. | FNA vol. 23, p. 155. |
Parent taxa | Cyperaceae > Cyperus > subg. Cyperus | Cyperaceae > Cyperus > subg. Pycnostachys |
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) | Vahl: Enum. Pl. 2: 325. (1805) |
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