Juncus effusus


Sp. Pl. 1: 326. 1753.

Common names: Soft rush
Synonyms: Juncus conglomeratus Linnaeus Juncus effusus var. brunneus Engelmann Juncus effusus var. caeruleomontanus H. St. John Juncus effusus var. costulatus FernaldSt. John Juncus effusus var. dicipiens Buchenau Juncus effusus var. exiguus Fernald & Wiegand Juncus effusus var. gracilis Hooker Juncus effusus var. pacificus Fernald & Wiegand Juncus effusus var. pylaei (Laharpe) Fernald & Wiegand Juncus effusus var. solutus Fernald & Wiegand Juncus effusus var. subglomeratus Lamarck & de Candolle Juncus griscomii Fernald Juncus pylaei Laharpe
Treatment appears in FNA Volume 22.

Herbs, perennial, 4–13 dm. Rhizomes short -branched, forming distinct, often large clumps. Culms erect, terete, 1–2.5 mm diam. at top of sheaths. Cataphylls several. Leaves: blade absent. Inflorescences lateral, compound dichasia, many flowered; primary bract erect, terete, extending well beyond dichasium. Flowers: tepals tan or darker, usually with greenish midstripe, lanceolate, 1.9–3.5 mm; inner slightly shorter; stamens 3, filaments 0.5–0.8 mm, anthers 0.5–0.8 mm; style 0.2 mm. Capsules greenish tan or darker, 3-locular, broadly ellipsoid to oblate, 1.5–3.2 mm. Seeds amber, (0.3–)0.4–0.5 mm. 2n = 40, 42.

Phenology: Flowering summer, fruiting summer–fall.
Habitat: Swamps and their edges, marshes, moist meadows, and moist or saturated soils, often conspicuous in pasture meadows where it is shunned by grazing animals
Elevation: Habitat??; 0–2500 m


V22 100-distribution-map.jpg

B.C., Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., P.E.I., Que., Ala., Alaska, 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.Y., N.C., Ohio, Okla., Oreg., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wash., W.Va., Wis.


The Juncus effusus complex has been variously recognized as containing several species or a single species with numerous infraspecific taxa. Unfortunately, North American treatments have dealt primarily with taxa in either the eastern or western portions of the continent. In considering the continent as a whole, little sense can be made of these treatments. The North American J. effusus complex is one that is in obvious need of modern systematic scrutiny.

Lower Taxa

... more about "Juncus effusus"
Ralph E. Brooks* +  and Steven E. Clemants* +
Linnaeus +
Soft rush +
B.C. +, Man. +, N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, P.E.I. +, Que. +, Ala. +, Alaska +, 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.Y. +, N.C. +, Ohio +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +, Wash. +  and Wis. +
Habitat?? +  and 0–2500 m +
Swamps and their edges, marshes, moist meadows, and moist or saturated soils, often conspicuous in pasture meadows where it is shunned by grazing animals +
Flowering summer, fruiting summer–fall. +
ahti1980a +  and fernald1910a +
Weedy +, Illustrated +  and Endemic +
Juncus conglomeratus +, Juncus effusus var. brunneus +, Juncus effusus var. caeruleomontanus +, Juncus effusus var. costulatus +, Juncus effusus var. dicipiens +, Juncus effusus var. exiguus +, Juncus effusus var. gracilis +, Juncus effusus var. pacificus +, Juncus effusus var. pylaei +, Juncus effusus var. solutus +, Juncus effusus var. subglomeratus +, Juncus griscomii +  and Juncus pylaei +
Juncus effusus +
Juncus subg. Genuini +
species +