Cyperus Sedge

In Great Britain and/or Ireland:
Plant / resting place / within
puparium of Cerodontha eucaricis may be found in leaf-mine of Carex pseudocyperus

Plant / resting place / on
adult of Donacia impressa may be found on Carex pseudocyperus

Foodplant / saprobe
stalked, occasionally sessile sporodochium of Myrothecium dematiaceous anamorph of Myrothecium cinctum is saprobic on dead leaf of Carex pseudocyperus
Remarks: season: 3-5

Foodplant / saprobe
colony of Periconia dematiaceous anamorph of Periconia curta is saprobic on dead stem of Carex pseudocyperus
Remarks: season: 1-12

Foodplant / saprobe
colony of Periconia dematiaceous anamorph of Periconia digitata is saprobic on dead stem of Carex pseudocyperus
Remarks: season: mainly winter

Foodplant / saprobe
colony of Periconia dematiaceous anamorph of Periconia funerea is saprobic on dead leaf of Carex pseudocyperus

Foodplant / parasite
uredium of Puccinia caricina var. caricina parasitises live Carex pseudocyperus

Foodplant / parasite
uredium of Puccinia urticata var. urticae-acutiformis parasitises live Carex pseudocyperus

Foodplant / saprobe
pycnidium of Stagonospora coelomycetous anamorph of Stagonospora caricinella is saprobic on dead leaf of Carex pseudocyperus

Foodplant / saprobe
scattered, subepidermal, fuscous pycnidium of Stagonospora coelomycetous anamorph of Stagonospora caricis is saprobic on dead leaf of Carex pseudocyperus
Remarks: season: 1-12

Foodplant / saprobe
pycnidium of Stagonospora coelomycetous anamorph of Stagonospora macropycnidia is saprobic on dead leaf of Carex pseudocyperus
Remarks: season: 11-5

Foodplant / saprobe
amphigenous, scattered or gregarious, immersed in parenchyma pycnidium of Stagonospora coelomycetous anamorph of Stagonospora paludosa is saprobic on dead stem of Carex pseudocyperus
Remarks: season: 9-4

Foodplant / saprobe
sporodochium of Volutella anamorph of Volutella arundinis is saprobic on dead leaf of Carex pseudocyperus

Foodplant / saprobe
sporodochium of Volutella anamorph of Volutella melaloma is saprobic on dead leaf of Carex pseudocyperus

Carex pseudocyperus is a smaller and more slender plant than C. comosa, but otherwise very similar. The two species often grow together where their ranges overlap and rarely produce sterile hybrids. Hybrids with C. hystericina are more frequent, and resemble C. pseudo- cyperus except for their sterility, the slightly more inflated and less reflexed perigynia, and the substantial red tinging on the basal sheaths.

Reported from Kashmir (C.B.Clarke, l.c. and R.R.Stewart, l.c.)

Plants densely to loosely cespitose; rhizomes short, no more than 10 cm. Culms trigonous in cross section, 25–100 cm, scabrous distally. Leaves: basal sheaths pale brown (rarely faintly red tinged); ligules usually much longer than wide; blades mid to dark green, flat to W-shaped, 4–13 mm wide, glabrous. Inflorescences 4–15 cm; proximal bract 12–55 cm, greatly exceeding inflorescence; proximal 2–5 spikes pistillate, erect or the proximal pendent, cylindric, 9–12 mm thick; terminal 1 spike staminate or, rarely, gynaecandrous, androgynous, or mixed. Pistillate scales lanceolate-acuminate, 2.5–8.6 × 0.3–0.6 mm, the distal shorter and the proximal longer than perigynia, margins ciliate, apex scabrous-awned. Staminate scales scabrous-awned, sometimes also ciliate-margined. Perigynia spreading to reflexed at maturity, strongly 12–20-veined, veins usually separated by less than 2 times their width, confluent at or proximal to mid beak (except for 2 prominent lateral), tightly investing achene, narrowly elliptic to lanceolate, 3.4–6.1 × 1–1.7 mm, leathery, apex gradually tapered; beak poorly defined, 1.2–2.2 mm, strongly bidentate, teeth straight or slightly out-curved, 0.7–1.2(–1.4) mm. Stigmas 3. Achenes pale brown, trigonous, smooth. 2n = 66.

Loosely tufted perennial, 60-120 cm. Rhizome short. Stem sharply trigonous, scabrous along edges. Leaves subbasal, flexuous, equalling or overtopping stem; sheaths 5-20 cm, yellowish or reddish, margin of scarious side concave; ligule up to 0.5 mm; blades 6-9 mm wide, flat, adaxial side scabrous along nerves, abaxial side less scabrous, margins and keel barbed. Inflorescence of terminal male spike and 3-5 female spikes below, close together, the latter drooping. Bracts much overtopping the inflorescence. Male spikes 22-62 x 3-5 mm, fusiform, cylindrical or club-shaped; male glumes 5.3-7.3 x 0.6-0.8 mm, incl. barbed arista 1.5-2.5 mm, ovate, yellowish-brown, scabrous, margins scarious. Female spikes 33-65 x 8-11 mm, cylindrical, peduncles 10-40)-140) mm; female glumes 3.3-6 x 0.6-0.8 mm, incl. barbed arista 2.3-5 mm, yellowish, apex scabrous, margins scarious; utricles 4.9-5.4 x 1.6-2.2 mm, with stipe 0.4-0.4 mm, ovoid, spreding-erect, later reflexed, strongly nerved, smooth, greenish yellow, beak 1.6-2.2 mm, cylindrical, smooth, with 2 long, rigid teeth. Stigmas 3. Nut 2-2.4 x 0.9-1.1 mm, including 0.4-0.8 mm style base, obovoid, trigonous, yellow or light brown, finely reticulate with a papilla in each areole.

Man., N.B., N.S., Ont., Que.; Conn., Maine, Mass., Mich., Minn., N.Y., Ohio, Pa., Vt., Wis.; Eurasia.

Distribution: Probably on all continents; Europe, Caucasus, Siberia, to Tian Shan Mts., Pamir and Kashmir; N. Africa, Syria, Israel, Turkey, Iran, Japan, N. America.

Fl. & Fr.: May – June.

Fruiting Jun–Aug.

Swamps, wet thickets, stream, pond, and lakeshores, depressions in wet meadows, marshes, often in shallow water or on emergent stumps, floating logs, floating mats of vegetation in water; 0–800m.

Wet wooded areas.

Carex pseudocyperus is a species of flowering plant in the sedge family known by the common name cyperus sedge or hop sedge. It grows in marshes, swamps, and the margins of ponds, rivers and canals. The stems can be up to 90 centimetres (35 in) with one male spike and 3 to 5 pendulous female spikes, and bright yellow-green leaves to 1.2 metres (3 ft 11 in).