Cyperus echinatus |
Cyperus seslerioides |
|
---|---|---|
globe flatsedge, teasel sedge |
Texas flatsedge |
|
Habit | Herbs, perennial, single-stemmed to loosely cespitose. | Herbs, perennial, cespitose; rhizomes knotty, much branched, 2–5 mm diam., scaly. |
Culms | basally cormlike, trigonous, (15–)30–100 cm × 0.5–3.5 mm, glabrous. |
roundly trigonous, basally with dark fibrous remnants of old leaf sheaths, (0.5–)4–30 cm × 0.4 –1.1 mm, glabrous. |
Leaves | flat to V-shaped, 10–65 cm × 3–9 mm, adaxial surface, margins minutely scabridulous. |
1–5, flat, involute toward apex, 3–18 cm × 1–2.5(–3) mm. |
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 hemispheric to spheric, (3–)6–15(–24) mm diam.; rays absent; bracts 2–5, horizontal to reflexed, parallel to culm, 1–13 cm × 1–3 mm, margins and keel sparsely minutely scabridulous distally. |
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. |
(5–)20–60(–100), whitish to greenish or brownish, ovoid to oblong-lanceoloid, compressed, 3–7 × 2–4 mm; floral scales (8–)10–12(–24), laterally milky white (infrequently yellowish, pale greenish, brown, or bronze-white), medially green or white, laterally ribless, medially 3-ribbed, ovate to ovate-lanceolate, 1.6–3(–3.4) × 0.8–1.3 mm, apex mucronate to acuminate. |
Flowers | anthers 0.4–0.8 mm; styles 0.5–0.6 mm; stigmas 1 mm. |
stamens 3; anthers linear, (0.4–)0.6–0.8(–1.1) mm, connective not prolonged; styles 0.8–1.8 mm; stigmas (0.5–)1–1.5(–2) 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 blackish, trigonous, broadly obovoid, 0.5–1 × 0.3–0.75 mm, base slightly stipelike, ± cuneate to rounded, apex apiculate, papillose. |
Cyperus echinatus |
Cyperus seslerioides |
|
Phenology | Fruiting summer–early fall. | Fruiting summer. |
Habitat | Disturbed, sunny sites, in mesic places, well-drained soils | Seeps, damp meadows in montane forests |
Elevation | 0–500 m (0–1600 ft) | 1000–2000 m (3300–6600 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
|
AZ; TX; Mexico; South America; Central America (Honduras) |
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. 182. | FNA vol. 23, p. 157. |
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) | Kunth: in A. von Humboldt et al., Nov. Gen. Sp. 1: 209. (1816) |
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