Juncus effusus

Linnaeus

Sp. Pl. 1: 326. 1753.

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

Distribution

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.

Discussion

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

None.
... more about "Juncus effusus"
persistent +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
Ralph E. Brooks* +  and Steven E. Clemants* +
Linnaeus +
Juncus effusus var. gracilis +  and Juncus griscomii +
channeled;terete +
darker +  and greenish tan +
broadly ellipsoid;oblate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.32 cm3.2 mm <br />0.0032 m <br />) +
distinct +
Soft rush +
1mm;2.5mm +
flowered +  and compound +
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 +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
arranged +  and cluster +
headlike +
Swamps and their edges, marshes, moist meadows, and moist or saturated soils, often conspicuous in pasture meadows where it is shunned by grazing animals +
3 +  and 1 +
green;brown or purplish black +
persistent +
Flowering summer, fruiting summer–fall. +
parietal +  and axile +
ahti1980a +  and fernald1910a +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
green;brown or purplish black +
persistent +
Weedy +, Illustrated +  and Endemic +
generally longer +
0.2 cm2 mm <br />0.002 m <br /> (?) +
Juncus conglomeratus +, Juncus effusus var. brunneus +, Juncus effusus var. caeruleomontanus +, Juncus effusus var. conglomeratus +, Juncus effusus var. costulatus +, Juncus effusus var. dicipiens +, Juncus effusus var. exiguus +, Juncus effusus var. pylaei +, Juncus effusus var. solutus +  and Juncus effusus var. subglomeratus +
Juncus effusus +
Juncus subg. Genuini +
species +
darker +  and tan +
lanceolate +
0.19 cm1.9 mm <br />0.0019 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +