Cyperus entrerianus |
Cyperus croceus |
|
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woodrush flatsedge |
Baldwin's flatsedge |
|
Habit | Herbs, perennial, coarse; rhizomes (seldom collected) indurate, oblique, 5–12 mm wide, with fibrous brown floral scales, 1–5 cm. | Herbs perennial, cespitose. |
Culms | 1–3, trigonous to roundly trigonous, (30–)40–65(–95) cm × (1–)2–3 mm. |
trigonous, (4–)14–45 cm × 1–2 mm, glabrous. |
Leaves | (1–)5–10, V-shaped, (10–)30–45(–70) cm × 3–7 mm. |
yellow-green, flat, 18–44 cm × 3–4.5 mm. |
Inflorescences | heads loosely to densely globose-ovoid, (6–)10–12(–20) mm diam.; rays 6–10(–12), 1–8(–12) cm; 2d order rays 1–4, 5–15(–23) mm; bracts (5–)6–8(–10), ascending at 45–60(–75)°, V-shaped, (5–)15–40(–55) cm × (1–)3–7 mm. |
spikes densely to loosely globose to ovoid, 10–20 mm wide; rays (3–)5–9(–14), 1–15(–26) cm; rachis 3–6(–9) mm; bracts (4–)6–9(–11), horizontal to ascending at 45°, flat, 1–30 cm × 0.5–4 mm; rachilla deciduous, wings persistent, 0.3–0.5(–0.8) mm wide. |
Spikelets | (1–)30–50(–65), greenish white, linear to broadly ellipsoid, flattened, 4–6.5 × 1.8–3.2 mm; floral scales (10–)16–20(–26), laterally clear, pale green, off-white, or light brown, medially green or light brown, laterally weakly 1-ribbed, medially 2-ribbed, basally 2-keeled, oblong-lanceolate, (1.2–)1.4–1.6(–1.8) × (0.7–)0.8–1 mm, apex acute, mucronate, distally glabrous or scabridulous. |
(10–)30–50, oblong to lanceoloid, quadrangular to subterete, compressed, 4–8 × 1–1.3 mm; distal spikelet spreading or ascending; floral scales persistent, (1–)2–4(–6), appressed, whitish with red speckles, laterally 2–4-ribbed, ovate, 2.3–3.6 × 1.8–2.2 mm. |
Flowers | stamen 1; anthers ellipsoid, 0.6–0.7 mm, connective apex acute, 0.1–0.2 mm; styles 0.2–0.4 mm; stigmas 0.4–0.6 mm. |
anthers 0.5 mm; styles 0.6–1.3 mm; stigmas 1.2–2.6 mm. |
Achenes | brown, stipitate, ellipsoid to narrowly ellipsoid, broadly rounded or contracted basally, gradually tapered toward apex, 0.9–1.1 × 0.3–0.4 mm, stipe 0.1 mm, apex acute, surfaces finely reticulate. |
reddish brown to nearly black, sessile, oblong, ellipsoid, 2–2.4 × 0.4–0.5(–0.7) mm, apex ± truncate-emarginate, apiculate, surfaces puncticulate. |
Cyperus entrerianus |
Cyperus croceus |
|
Phenology | Fruiting summer. | Fruiting summer–early fall. |
Habitat | Roadside ditches, marshes | Disturbed, sunny areas, coastal rocks, moist thickets |
Elevation | 0–100 m (0–300 ft) | 0–200 m (0–700 ft) |
Distribution |
AL; FL; GA; LA; MS; TX; Mexico; South America; Central America (Nicaragua) [Introduced in North America]
|
AL; AR; DE; FL; GA; LA; MD; MO; MS; NC; NJ; OK; PA; SC; TN; TX; VA; WV; Mexico; Central America; West Indies; South America (Venezuela)
|
Discussion | Cyperus entrerianus is a recent introduction in the southern United States (earliest collection from Pensacola County, Florida, Brinker 413, MO in 1941). It has been confused with C. luzulae. The species that Boeckeler had first described 50 years earlier was accepted by G. Kükenthal (1935–1936). Cyperus entrerianus was accepted as a variety of C. luzulae by A. B. Ayers (1946); M. F. Denton (1978b) considered C. entrerianus a synonym of C. luzulae, stating that the features of these two taxa merged so completely throughout their geographic ranges that C. entrerianus could not be given specific status. Cyperus luzulae in the strict sense does not extend northward to North America. Morphologic differences between Cyperus entrerianus and C. luzulae are as follows (G. C. Tucker 1994). Cyperus entrerianus has culms 40–75 cm; inflorescence bracts ascending at 45–60°; primary rays ascending at 45–60(–75)°; 2d order rays present; heads of spikelets loosely globose-ovoid, light greenish white to golden brown; rachilla dark red with stramineous scale scars; and scale apices acute. Cyperus luzulae has culms 20–40 cm; inflorescence bracts approximately horizontal; primary rays ascending at 15–30°; 2d order rays absent; heads of spikelets densely oblong to pyramidal, bright to dull white; rachilla green throughout; and scale apices rounded. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Cyperus globulosus Aublet is a synonym of C. luzulae (Linnaeus) Rottbøll ex Retzius, which is a widespread neotropical species, and it has long been misapplied to Cyperus croceus (G. C. Tucker 1987). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 23. | FNA vol. 23, p. 183. |
Parent taxa | Cyperaceae > Cyperus > subg. Pycnostachys | Cyperaceae > Cyperus > subg. Cyperus |
Sibling taxa | ||
Synonyms | C. luzulae var. entrerianus | C. baldwinii, C. cyclostachyus, C. echinatus var. multiflora, C. globulosus var. pseudofiliculmis, C. globulosus var. robustus, C. plankii, C. retrorsus var. robustus, Mariscus bracheilema, Mariscus brittonii |
Name authority | Boeckeler: Flora 61: 139. (1878) | Vahl: Enum. Pl. 2: 357. (1805) |
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