Cyperus entrerianus Boeckeler

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.

Herbs, perennial, coarse; rhizomes (seldom collected) indurate, oblique, 5–12 mm wide, with fibrous brown floral scales, 1–5 cm. Culms 1–3, trigonous to roundly trigonous, (30–)40–65(–95) cm × (1–)2–3 mm. Leaves (1–)5–10, V-shaped, (10–)30–45(–70) cm × 3–7 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. 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. 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. 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.

introduced; Ala., Fla., Ga., La., Miss., Tex.; Mexico; Central America (Nicaragua); South America.

Fruiting summer.

Roadside ditches, marshes; 0–100m.

Cyperus luzulae (Linnaeus) Rottbøll ex Retzius var. entrerianus (Boeckeler) Barros

Cyperus entrerianus, commonly known as the woodrush flatsedge, is a species of sedge that is native to southern parts of North America, Central America, and parts of South America.

The species was first formally described by the botanist Johann Otto Boeckeler in 1878.

Cyperus entrerianus adalah spesies tumbuhan yang tergolong ke dalam famili Cyperaceae. Spesies ini juga merupakan bagian dari ordo Poales. Spesies Cyperus entrerianus sendiri merupakan bagian dari genus Cyperus. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh Boeckeler.

Cyperus entrerianus là loài thực vật có hoa trong họ Cói. Loài này được Boeckeler mô tả khoa học đầu tiên năm 1878.