Lesser Pond Sedge

Foodplant / saprobe
superficial pseudothecium of Acanthophiobolus helicosporus is saprobic on dead leaf of Carex acutiformis
Remarks: season: 5-10

Foodplant / saprobe
subclypeate perithecium of Anthostomella limitata is saprobic on dead leaf of Carex acutiformis
Remarks: season: 4-12

Foodplant / saprobe
immersed, clypeate perithecium of Anthostomella punctulata is saprobic on dead leaf of Carex acutiformis
Remarks: season: 2-10
Other: minor host/prey

In Great Britain and/or Ireland:
Foodplant / saprobe
colony of Arthrinium dematiaceous anamorph of Apiospora montagnei is saprobic on dead stem of Carex acutiformis

Foodplant / saprobe
sporodochium of Arthrinium dematiaceous anamorph of Arthrinium caricicola is saprobic on often dry, bleached, dead leaf of Carex acutiformis
Remarks: season: 4-7

Foodplant / saprobe
colony of Arthrinium dematiaceous anamorph of Arthrinium phaeospermum is saprobic on dead leaf of Carex acutiformis
Remarks: season: esp. 7-8
Other: minor host/prey

Foodplant / saprobe
sporodochium of Arthrinium dematiaceous anamorph of Arthrinium puccinioides is saprobic on often dry, bleached, dead leaf of Carex acutiformis
Remarks: season: (1-)3-5(-12)

Foodplant / saprobe
sporodochium of Arthrinium dematiaceous anamorph of Arthrinium sporophleum is saprobic on newly dead leaf of Carex acutiformis
Remarks: season: 3-4

Foodplant / saprobe
subiculate apothecium of Belonopsis asteroma is saprobic on dead, often reddened leaf base of Carex acutiformis
Remarks: season: 4-11

Foodplant / spot causer
immersed, clypeate pseudothecium of Buergenerula biseptata causes spots on live leaf of Carex acutiformis
Remarks: season: 12-1

Foodplant / saprobe
immersed perithecium of Ceriophora palustris is saprobic on dead leaf of Carex acutiformis
Remarks: season: 3-8

Plant / resting place / within
puparium of Cerodontha eucaricis may be found in leaf-mine of Carex acutiformis

Foodplant / saprobe
sporodochium of anamorph of Ciboria aschersoniana is saprobic on old, blackened fruit of Carex acutiformis
Remarks: season: 10-2
Other: uncertain

Foodplant / saprobe
extensive, hypophyllous, velvety colony of Clasterosporium dematiaceous anamorph of Clasterosporium caricinum is saprobic on dead leaf of Carex acutiformis
Remarks: season: 1-12
Other: major host/prey

Foodplant / saprobe
immersed pseudothecium of Didymella proximella is saprobic on dead leaf of Carex acutiformis
Remarks: season: 3-7

Foodplant / open feeder
adult of Donacia aquatica grazes on windowed leaf (upper surface) of Carex acutiformis
Remarks: season: 5-7(-10)

Foodplant / feeds on
adult of Donacia impressa feeds on pollen of Carex acutiformis
Remarks: season: 5-6
Other: major host/prey

Foodplant / feeds on
adult of Donacia thalassina feeds on pollen of Carex acutiformis
Remarks: season: 5
Other: uncertain
Other: major host/prey

Foodplant / saprobe
fruitbody of Epithele typhae is saprobic on dead leaf base of Carex acutiformis
Other: major host/prey

Foodplant / parasite
sorus of Farysia thuemenii parasitises live inflorescence of Carex acutiformis
Remarks: Other: uncertain

Foodplant / pathogen
immersed, mycelial matted perithecium of Gaeumannomyces graminis infects and damages dead leaf sheath (lower part) of Carex acutiformis
Remarks: season: 3-10

Foodplant / saprobe
apothecium of Lachnum carneolum var. longisporum is saprobic on dead leaf of Carex acutiformis
Remarks: season: (2-)6-8(-10)
Other: minor host/prey

Foodplant / saprobe
effuse colony of Periconia dematiaceous anamorph of Massarina igniaria is saprobic on dry, scorched or burnt Carex acutiformis
Remarks: season: 8-12

Foodplant / saprobe
immersed pseudothecium of Metasphaeria cumana f. macrospora is saprobic on dead leaf of Carex acutiformis
Remarks: season: 7-8

Foodplant / saprobe
superficial, sessile, clypeate apothecium of Micropeziza cornea is saprobic on dead stem of Carex acutiformis
Remarks: season: 3-7

Foodplant / saprobe
shortly stipitate apothecium of Microscypha ellisii is saprobic on dead leaf of Carex acutiformis
Remarks: season: 4-8

Foodplant / saprobe
sessile apothecium of Mollisia dactyligluma is saprobic on glume of Carex acutiformis
Remarks: season: 6-7

Foodplant / saprobe
sessile apothecium of Mollisia palustris is saprobic on dead stem of Carex acutiformis
Remarks: season: 3-9

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

Foodplant / saprobe
scattered, immersed, amphigenous pycnidium of Neottiospora coelomycetous anamorph of Neottiospora caricina is saprobic on dead leaf of Carex acutiformis
Remarks: season: 3-8

Foodplant / saprobe
superficial perithecium of Niesslia exosporioides is saprobic on dry, dead leaf of Carex acutiformis
Remarks: season: 4-8

Foodplant / saprobe
apothecium of Niptera pilosa is saprobic on dead leaf (base) of Carex acutiformis
Remarks: season: 2-9

Foodplant / saprobe
colony of Periconia dematiaceous anamorph of Periconia atra is saprobic on dead leaf of Carex acutiformis
Remarks: season: 4-9

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

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

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

Foodplant / saprobe
effuse colony of Periconia dematiaceous anamorph of Periconia hispidula is saprobic on dry, dead leaf of Carex acutiformis
Remarks: season: 1-12

Foodplant / saprobe
effuse colony of Periconia dematiaceous anamorph of Periconia laminella is saprobic on dead stem of Carex acutiformis

Foodplant / saprobe
effuse colony of Periconia dematiaceous anamorph of Periconia minutissima is saprobic on dead leaf of Carex acutiformis
Remarks: season: 1-12

Foodplant / spot causer
punctiform, scattered singly or in lines, mainly epiphyllous, black, covered then piercing pycnidium of Phaeoseptoria coelomycetous anamorph of Phaeoseptoria caricicola causes spots on dead leaf of Carex acutiformis
Remarks: season: 4-9

Foodplant / saprobe
immersed apothecium of Phragmonaevia hysterioides is saprobic on dead, dry leaf of Carex acutiformis
Remarks: season: 6-9

Foodplant / saprobe
amphigenous colony of Arthrinium dematiaceous anamorph of Physalospora scirpi is saprobic on often dry, bleached, dead leaf of Carex acutiformis
Other: minor host/prey

Foodplant / saprobe
apothecium of Psilachnum eburneum is saprobic on dead leaf of Carex acutiformis
Remarks: season: 4-9
Other: minor host/prey

Foodplant / saprobe
apothecium of Psilachnum lateritioalbum is saprobic on dead leaf of Carex acutiformis
Remarks: season: 7-8

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

Foodplant / saprobe
pycnidium of Stagonospora coelomycetous anamorph of Stagonospora anglica is saprobic on dead leaf of Carex acutiformis
Remarks: season: 11

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

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

Foodplant / saprobe
pycnidium of Stagonospora coelomycetous anamorph of Stagonospora macropycnidia is saprobic on dead leaf of Carex acutiformis
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 acutiformis
Remarks: season: 9-4

Foodplant / saprobe
Mirandina dematiaceous anamorph of Taphrophila cornu-capreoli is saprobic on dead leaf of Carex acutiformis

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

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

An uncommon and local introduction, Carex acutiformis forms large, glaucous clones where it is established but is, as yet, not spreading aggressivly into adjacent habitats. It superficially resembles C. aquatilis, but is larger, has 3 stigmas, and has strongly veined perigynia 3–4.5 mm.

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

Plants colonial; rhizomes long-creeping. Culms central, coarse, trigonous, 55–130 cm, scabrous-angled. Leaves: basal sheaths pale green to brownish or red tinged; ligules 5–14 mm; blades glaucous, M-shaped, (4.5–)5.5–12(–20) mm wide, glabrous. Inflorescences 15–35 cm; proximal 2–5 spikes pistillate, ascending; distal spikes erect; terminal 1–2(–3) spikes staminate. Pistillate scales lanceolate, acute to acuminate, glabrous, at least the proximal with scabrous awn to 3.5 mm. Perigynia ascending, ± glaucous, often strongly red dotted, ± strongly 12–18-veined, thin-walled, narrowly ovoid, flattened-trigonous, 3–4.5 × 1.4–2.1 mm, glabrous; beak 0.3–0.6 mm, emarginate to weakly bidentulate, teeth to 0.2 mm. 2n = 78.

Stoloniferous perennial, 60-120 cm. Stem acutely trigonous, 1.5-3 mm diam., frequently papillose, smooth or scabrous along edges. Leaves to as long as stems; sheaths to 15 cm, septate, greyish brown, frequently with a red tint, disintegrating into fibres; ligule to 0.5 mm; blades (3-)4-6 mm wide, flat or margins revolute, long-acuminate, densely grey papillose below, margins and keel scabrous, upper surface smooth. Inflorescence with (1-)2-3 male and 2-3(-4) female spikes. Bracts sheath-less, lowest overtopping inflorescence. Male spikes (15-)20-40 x 3-5 mm, cylindrical, dark brown; glumes 4-5 x 1.3-1.6 mm, lanceolate, dark brown. Female spikes (15-)25-60 x 4-6 mm, cylindrical, erect or spreading-erect, lowest with peduncle to 40 mm; glumes 2.5-4 x 0.7-1.2 mm, ovate, acute or acuminate, dark-brown; utricles 2.8-4.1 x 1.6-2.1 mm, ellipsoid, greenish or greyish brown, sometimes with reddish tint, nerves prominent, upper part papillose and sometimes glandular punctate, beak 0.3-0.5 mm, cylindrical, papillose, shallowly bidentate. Stigmas 3, occasionally 2. Nut 1.8-2.3 x 1.2-1.3 mm, incl. c. 0.3 mm persistent style base, obovoid, trigonous, brown, finely reticulate with papilla in each areole.

introduced; Ont.; Conn., Ind., Mass., Md., Mich., N.Y.; Eurasia; Africa.

Distribution: Europe, Africa, Turkey, Caucasus, Iran, Siberia and southwards in C. Asia from Altai to Afghanistan, Pakistan and Kashmir.

Fl. Per.: April - May (- September).

Fruiting Jun–Aug.

Open swamps, wet, open thickets, marsh edges, sedge meadows, lakeshores; 0–300m.

Forested areas, on moist ground around ponds and along rivers; 100-2200 m.

C. paludosa Good. in Trans. Linn. Soc. 2: 202. 1794.

Carex acutiformis Ehrh. Beitr. 4: 43. 1789
Carex vesicaria var. Leers, Fl. Herborn. 205. pi. 16, f. 2 I. 1775. (Type from Germany.)
"Carex acuta L." Curt. Fl. Lond. 4: pi. 61. 1783. (Plant from England.)
Carex palustris J. F. Gmel. Syst. Nat. 2 : 145. 1791. (Type from Switzerland.)
Carex spadicea Roth, Fl. Germ. 2 2 : 461. 1793. (Type from Germany.) Not C. spadicea J. F. Gmel.
1791. Carex paludosa Gooden. Trans. Linn. Soc. 2: 202. 1794. (Type from England.) Carex dubia Hose, Ann. Bot. Usteri 21 : 34. 1797. (Type from near Krefeld, Germany.) Carex riparia Genersich, Fl. Seep. Elench. no. 874. 1798. Not C. riparia Curt. 1783. Carex rigens Thuill. Fl. Par. ed. 2. 488. 1799. (Type from Paris, France.) Carex intermedia Suter, Fl. Helv. 2 : 262. 1802. (Type from Switzerland.) Carex Kochiana DC. Cat. PI. Hort. Monsp. 89. 1813. Carex litloralis Krocker, Fl. Siles. 3: 163. 1814. (Type from Silesia.)
Trasus paludosus S. F. Gray, Nat. Arr. Brit. PI. 2 : 64. 1821. (Based on Carex paludosa Gooden.) Carex aemulans Liebm. & Drejer; Drejer, Fl. Exc. Hafn. 291, in part. 1838. (Type from Denmark.) Edrilria paludosa Raf. Good Book 26. 1840. (Based on Carex paludosa Gooden.) Carex paludosa var. minor Peterm. Anal. Pfl. 516. 1846. (Type from Leipzig, Germany.) Carex Jaegeri F. Schultz, Fl. Pfalz 507. 1846. (Type from Germany.) Carex paludosa f. depauperata Lange, Bot. Notiser 1849: 165. 1849. Carex glauca X paludosa F. Schultz, Flora 37: 471. 1854.
Carex spadicea var. Kochiana Asch. Fl. Brand. 1 : 793. 1864. (Based on C. Kochiana DC.) Carex spadicea f. maxima Urban, Verh. Bot. Ver. Prov. Brand. 22 : 54. 1880. (Type from Germany.) Carex Olgae Regel, Izv. Obsht. Lyub. Estestv. 34=:, 83. 1882. (Type from near Samarkand.) Carex paludosa var. longiglumis St. -Lag. in Cariot, Etude Fl. ed. 8. 2: 865. 1889. . Carex acutiformis var. abbreviata G. Beck, Fl. Nieder-Oesterr. 143. 1890. Carex glauca X acutiformis Asch. & Graebn. Fl. Nordostd. Flachl. 169. 231. 1898. Carex acutiformis f. spadicea Asch. & Graebn. Fl. Nordostd. Flachl. 215. 1898. Carex acutiformis f. gracilior Kneucker, Allg. Bot. Zeits. 5: Beih. 64. 1899. Carex acutiformis f. depauperata " Lange " Kukenth. in Engler, Pflanzenreich 4-°: 734. 1909. (Based
on C. paludosa f. depauperata Lange.) Carex acutiformis f. maxima Kukenth. in Engler, Pflanzenreich 4 2 °: 734. 1909. (Based on C. spadicea
f. maxima Urban.) Carex aculiformis i. minor "Peterm." Kukenth. in Engler, Pflanzenreich 4=»: 734. 1909. (Based on
C. paludosa var. minor Peterm.) Loosely cespitose and strongly stoloniferous, the stolons horizontal, stout, scaly, the culms 4-12 dm. high, erect, stout below, slender above, exceeding the leaves, sharply triangular, much roughened above, strongly reddish-purple at base, clothed at base with the dried-up leaves of the previous year, the lower leaves of the year's growth bladeless or nearly so, their sheaths breaking and strongly filamentose; sterile shoots elongate, strongly aphyllopodic; leaves with well-developed blades 5-12 to a fertile culm, on the lower third, the lower clustered, septate-nodulose, the blades channeled below, flat with revolute margins above, firm, lightgreen or somewhat glaucous-green (at least beneath), usually 2-4 dm. long, 4-9 mm. wide, roughened towards the slender apex, the sheaths thin, smooth, deeply concave at mouth, the ligule as long as wide; staminate spikes 2-4, sessile or the uppermost short-peduncled, 2-6 cm. long, 4-6 mm. wide, the scales oblong-oblanceolate, obtuse to awned, purplish-brown with obscure lighter center and very narrow white-hyaline margins; pistillate spikes 3 or 4, widely separate, erect, the upper sessile and often staminate at apex, the lower shortor long-peduncled, linear or linear-oblong, 3-13 cm. long, 5-7 mm. wide, densely flowered, containing 40-100 appressed-ascending perigynia in several to many rows ; lower bracts leaflet-like, not sheathing, nearly equaling or exceeding inflorescence, the upper reduced, scales lanceolate, awned, acuminate, or acute, purplish-brown with lighter 3-nerved center and narrow hyaline margins, narrower than but the more developed ones exceeding the perigynia; perigynia ovoid, 3-4 mm. long, 1.5 mm. wide, flattened-oval in cross-section, or obtusely triangular at maturity, more or less subcoriaceous, red-dotted, papillate, olive-green, somewhat glaucous, inflated, rather strongly several-ribbed, rounded or round-tapering at base, stipitate, tapering at apex into a short (0.5 mm. long), slightly subserrulate, conic beak with emarginate or shallowly bidentate colored orifice; achenes oblong-ovoid or oblong-obovoid, 2 mm. long, 1.25 mm. wide, triangular with slightly concave sides and blunt angles, somewhat loosely enveloped, granular, brownishblack, nearly sessile, short-tapering at apex and continuous with the short, straight, slender style; stigmas 3, dark-reddish-brown, slender.
Type locality: "Habitat in paludosis Brunsvico-Luneburgicis."
Distribution: Boggy meadows, very locally naturalized from Europe in eastern Massachusetts. Widely distributed in Eurasia and Africa. (Specimens examined from Massachusetts.)

Carex acutiformis, the lesser pond-sedge, is a species of sedge.