Fox Tail Flat Sedge

Cyperus alopecuroides has been introduced in Polk County, Florida.

Plants of Cyperus alopecuroides might be confused with C. digitatus; large size and the biconvex achenes with two stigmas characterize C. alopecuroides.

Herbs, perennial, rhizomatous, coarse. Culms trigonous, 150–250 cm × 2–15 mm, glabrous. Leaves inversely W-shaped, 30–150 cm × 6–22 mm. Inflorescences: spikes 1–4, cylindric, 1.5–4 cm × 7–15 mm; rays 3–9, 10–26 cm; 2d order rays 2–11 cm; 3d order rays 1–4 cm (or absent); bracts 3–5, ± horizontal, 20–100 cm × 3–15 mm; 2d order bracts 2–7 cm × 2–7 mm; 3d order bracts 2–5 cm × 2–4 mm (or absent); rachilla persistent, wingless or wing hyaline, narrow, 0.1 mm wide. Spikelets 50–100, linear, ± quadrangular, slightly compressed, 8–11 × 0.9–1.2 mm; floral scales 15–30, marginally clear, laterally reddish along midrib, medially green, laterally 3–4 ribbed, medially 3–5-ribbed, ovate, 1–2–1.6 × 1.1–1.3 mm, apex mucronulate. Flowers: anthers 2, 0.4–0.5 mm; styles 0.8–1 mm; stigmas 2, 0.4 mm. Achenes dark brown, sessile, ellipsoid to obovoid, 0.9 × 0.4–0.5 mm, surfaces finely puncticulate.

Caespitose (perennial?), 70-120 cm. Rhizome 0(?). Roots glabrous. Stem 5-7 mm diam., trigonous, green, smooth. Leaves up to as long as stem, stiff below, curved and somewhat flexuous above; sheaths 5-20 cm, brown or greyish, rather soft; blades to c. 15 mm wide, base turgid, somewhat keeled, margins smooth, margins and main nerves towards apex scabrous above, apex long tapering, trigonous, scabrous. Inflorescence a compound anthelodium, to 35 cm; bracts 5-7, foliose, 2-4 longer than inflorescence, to more than 50 cm; primary branches 5-15, to 30 cm, most of them rebranching, secondary anthelodia to 12 cm, longest secondary branches sometimes with small tertiary anthelodium, tubular prophyll to 35 mm, with small leaf blade, to 15 mm; cluster of spikes of 25-c.50 tightly spirally arranged spikes. Spikes c. 5 mm x 3 mm, ovoid, flat, spreading, flat side upwards, glume-like bract c. 2.5 mm, acute, glume-like prophyll bi-nerved, clasping, c. 1 mm; rachis flat, c. 0.3 mm wide, quadrangular, narrowly winged, internodes c. 0.5 mm; glumes 2-2.5 mm, cymbiform, blunt or mucronate, sides with raised nerves, yellowish or grey, with reddish-brown stripes, margins yellowish or pale, scarious. Stamens 2; stigmas 2 or 3. Nut c. 0.5 mm, yellowish brown, bi-convex, slightly flattened, finely reticulate or almost smooth, shiny.

introduced; Fla.; West Indies; Asia; Africa; Australia.

Distribution: In N. and tropical Africa, Madagascar, Macaronesia; West Indies, Guadeloupe; Pakistan, India, Malaysia, NE Australia.

Fl. Per.: April, September. According to Bhandari, Fl. Indian Desert (1990) flowering and fruiting from Oct. to March.

Fruiting summer.

Pond shores, stream banks; 0–30m.

Swamps, alluvial areas.

Juncellus alopecuroides (Rottb.) C.B. Clarke, Fl. Brit. Ind. 6: 595. 1893; Rottb., Descr. & Icon.: t. VIII, fig. 2. 1773. Täckholm, Stud. Fl. Egypt: Pl. 292. 1974. Haines & Lye, Sedges and Rushes E. Afr.: fig. 384. 1983.