Bearded Flatsedge

Cyperus squarrosus can be recognized by its small size and annual habit combined with its oblong-lanceolate floral scales bearing five to eleven conspicuous ribs and excurved awns. Some collections have been misidentified as C. acuminatus, an annual species of subg. Pycnostachys that has ovate-lanceolate, three-ribbed floral scales and digitately clustered spikelets.

Herbs, annual, cespitose, with fibrous roots. Culms 1–20, trigonous, 2–16 cm × 0.5–0.8 mm, glabrous. Leaves 1–3, flat to V-shaped, (1–)5–10(–15) × 0.5–2.5 mm. Inflorescences: spike 1, loosely to densely ovoid to oblong, 6–20(–40) × 9–15(–20) mm; rays absent or 1–3(–6), 4–40 mm; bracts (1–)2–4, longest ± erect, V-shaped, 1–15 cm × 0.5–3 mm; rachilla ± deciduous, wingless. Spikelets (2–)6–20(–40), greenish to reddish brown, somewhat compressed, ovoid-lanceoloid to oblong, 2.5–10(–20) × 1.3–2.2 mm (excluding awns); floral scales deciduous, (4–)10–20(–34), greenish to stramineous or brownish red laterally, greenish medially, (5–)7–9(–11)-ribbed nearly to margins, oblong-lanceolate, (1.2–)1.3–1.8(–2.2) × (0.5–)0.7–0.8(–1) mm, apex cuspidate, excurved awn additional 0.5–1(–1.3) mm. Flowers: stamen 1, filaments 1.5 mm; anthers oblong, 0.2–0.3 mm, connective apex reddish, minute; styles 0.3–0.5 mm; stigmas 0.4–0.7 mm. Achenes light brown to nearly black, stipitate, obovoid (occasionally linear-spatulate or linear oblong, infrequently constricted in middle), 0.7–0.8(–1.1) × (0.2–)0.3–0.4(–0.5) mm, stipe 0.05–0.1 × 0.1 mm, apex truncate, apiculate, surfaces papillose.

Tufted annual, 5-20 cm. Stem 0.5-1.5 mm diam., sharply trigonous, or even winged, greyish-green, smooth. Leaves basal or subbasal, from half to as long as stems; sheaths 7-50 mm, reddish or yellowish brown or greenish, mouth margin slightly concave; ligule 0; blades up to 10 cm, 1-3 mm wide, greyish-green, keeled, margins smooth, slightly revolute, apex acute and slightly scabrous or smooth. Inflorescence a small multiple spike, up to 50 mm, seldom a single cluster of spikes; clusters rounded or elongated, with 2 to more than 30 spirally arranged spikes; primary branches 0-4, up to 45 mm, tubular prophyll often reddish, up to 5 mm; 2-3 bracts foliose, to 13 cm, longer than inflorescence. Spikes reflexed, flat, ovoid, to 7 mm x 2.5-3 mm, with from 4 to more than 10 flowers; glume-like bract 0.5-1 mm, acute, glume-like prophyll scarious, 2-veined, from 0.7 up to more than 1 mm; rachis compressed, 4-angled, internodes c. 0.5 mm, green, later reddish-brown; glumes 1.5-2.3 mm, cymbiform, sometimes keeled, not truncate, mid-nerve green, extending into recurved arista up to 0.7 mm, sides pale greenish or reddish brown, with 3(-4) nerves, scarious. Stamens 1-2. Nut 0.7-1 mm, obovoid, trigonous, brown or dark brown, papillose.

Alta., B.C., Man., N.B., Ont., Que.; Ala., Ariz., Ark., Calif., Colo., Conn., Del., D.C., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah., Vt., Va., Wash., W.Va., Wis., Wyo.; Mexico; West Indies; Bermuda; Central America; South America; Eurasia; Africa; Atlantic Islands; Indian Ocean Islands; Pacific Islands; Australia.

Distribution: Africa S of Sahara to S Africa, Madagascar, Pakistan, India and China to Australia, N and S. America.

Fl. Per.: August - September (to Dec., according to Bhandari 1990, as Mariscus squarrosus).

Fruiting summer.

Moist, disturbed soils, gravelly roadsides, flood plains, edges of puddles, muddy places; 0–2500m.

Open moist ground, grasslands, on rocks and sand, to c.2100 m; also as weed.

Chlorocyperus inflexus (Muhlenberg) Palla; Cyperus aristatus Rottbøll; C. aristatus var. inflexus (Muhlenberg) Kükenthal; C. aristatus var. runyonii O’Neill; C. inflexus Muhlenberg; Dichostylis aristata (Rottbøll) Palla; Mariscus squarrosus (Linnaeus) C. B. Clarke

C. aristatus Rottb., Descr. Pl. Rar. Progr.: 22. 1772; Kük. in Engler, Pflanzenreich IV.20, 101: fig. 55, F-J (1936 as C. aristatus); R. R. Stewart, l.c. 92. 1972; U. Scholz in H. Scholz & U. Scholz, Fl. Gramin. & Cypér. Togo: Fig. 19. 1983; Kukkonen in Rech.f., l.c. 129.

squarrosus: squarrose

Cyperus squarrosus is a species of sedge known by several common names, including bearded flatsedge and awned flatsedge. It is found in wet environments in North and South America, Africa, Australia, southern Asia (China, India, Saudi Arabia, Indochina, etc.) and Italy.