Cyperus cuspidatus |
Cyperus echinatus |
|
---|---|---|
coastal plain flatsedge |
globe flatsedge, teasel sedge |
|
Habit | Herbs, annual, cespitose. | Herbs, perennial, single-stemmed to loosely cespitose. |
Culms | 1–6(–25), trigonous to roundly trigonous, (0.5–)2–5(–9) cm × 0.2–0.4–(0.6) mm, glabrous. |
basally cormlike, trigonous, (15–)30–100 cm × 0.5–3.5 mm, glabrous. |
Leaves | 1–6, V-shaped, 1–6 cm × 0.3–1 mm. |
flat to V-shaped, 10–65 cm × 3–9 mm, adaxial surface, margins minutely scabridulous. |
Inflorescences | heads digitate, loosely ovoid, 3–18 × 3–26 mm; rays (0–)1–6(–8), 2.5–20(–30) mm; bracts 2–3(–5), horizontal to ascending at 45(–60)°, V-shaped, 2–60 × 0.3–1.2 mm. |
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. |
Spikelets | (3–)10–20(–30), greenish to reddish brown, narrowly ellipsoid to oblong, 3–11 × (0.8–)1.2–1.5 mm; floral scales (3–)6–20(–28), laterally greenish to reddish brown, glossy, medially greenish to light reddish brown, strongly recurved, laterally ribless, medially strongly 3-ribbed, oblong-ovate, (0.8–)1–1.3 × 0.8–1(–1.2) mm, apex emarginate, cusp 0.6–1.2 mm. |
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. |
Flowers | stamens 2 or 3; anthers oblong-ovoid, 0.1(–0.2) mm; styles (0.2–)0.4–0.6 mm; stigmas 0.3–0.5 mm. |
anthers 0.4–0.8 mm; styles 0.5–0.6 mm; stigmas 1 mm. |
Achenes | brown, oblong-obovoid, (0.5–)0.6 × (0.3–)0.4 mm, base cuneate, apex blunt, surfaces coarsely papillose. |
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. |
Cyperus cuspidatus |
Cyperus echinatus |
|
Phenology | Fruiting summer. | Fruiting summer–early fall. |
Habitat | Damp, disturbed soils | Disturbed, sunny sites, in mesic places, well-drained soils |
Elevation | 0–300 m (0–1000 ft) | 0–500 m (0–1600 ft) |
Distribution |
AL; FL; GA; SC; Mexico; Central America; South America
|
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
|
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.) |
|
Source | FNA vol. 23, p. 158. | FNA vol. 23, p. 182. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | 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 | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 204. (1816) | (Linnaeus) Alph. Wood: Class-book Bot. ed. s.n.(b), 734. (1861) |
Web links |