Juncus canadensis

J. Gay ex Laharpe

in J. J. C. de Laharpe,Essai Monogr. Jonc. 46. 1825.

Common names: Canada rush
IllustratedEndemic
Synonyms: Juncus canadensis var. longicaudatus Engelmann Juncus canadensis var. sparsiflorus Fernald Juncus longicaudatus Juncus polycephalus var. paradoxus Torrey
Treatment appears in FNA Volume 22.

Herbs, perennial, cespitose, 3–10 dm. Culms erect, 1–5 mm diam., smooth. Cataphylls 0 or 1–2, straw-colored, apex rounded. Leaves: basal 1, cauline 2–3; auricles 1–1.2 mm, apex rounded, scarious; blade terete, 7–22 cm × 1.2–3 mm. Inflorescences panicles or racemes of 3–50 heads, 2–20 cm, branches erect to ascending; primary bract erect; heads 5–50-flowered, obconic to spheric, 3–10 mm diam. Flowers: tepals green or straw-colored to reddish-brown, lanceolate; outer tepals 2.7–3.8 mm, apex acuminate; inner tepals 2.9–4 mm, apex acuminate; stamens 3 (–6), anthers 1/2 filament length. Capsules equaling perianth or exserted, chestnut-brown, imperfectly 3-locular, lanceoloid, 3.3–4.5 mm, acute proximal to beak, valves separating at dehiscence. Seeds fusiform, 1.1–1.9 mm, tailed; body covered with whitish translucent veil. 2n = 80.


Phenology: Fruiting mid summer–fall.
Habitat: Salt, brackish, and calcareous marshes, acid bogs, roadsides, tidal flats, swamps, patterned fen, lake shores, beaches
Elevation: 0–200 m

Distribution

V22 431-distribution-map.jpg

St. Pierre and Miquelon, Man., N.B., Nfld. and Labr. (Nfld.), N.S., Ont., Oreg., P.E.I., Que., Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., S.Dak., Tenn., Vt., Va., W.Va., Wis.

Discussion

Two varieties and two forms occurring within the flora have been recognized (M. L. Fernald 1945b). Juncus canadensis var. sparsiflorus has stiffly erect inflorescence branches, and the flowers are generally longer than those of var. canadensis. These varieties simply serve to give name to parts of the broad morphologic range of variation encountered in J. canadensis and do not appear to represent any distinct biological entities.

Juncus canadensis and the following three species form a distinctive group: they have ve been variously treated as speecies (as here), varieties of J. canadensis, or as two species, J. canadensis and a polymorphic species, J. brachysephalus, encompassing the other three species (B. Boivin 1967–1979, part IV). Most of the species are easily recognized at their extremes but show a fair amount of overlap.

Selected References

None.

Lower Taxa

None.
... more about "Juncus canadensis"
persistent +
acuminate +  and rounded +
scarious +
0.1 cm1 mm <br />0.001 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Ralph E. Brooks* +  and Steven E. Clemants* +
J. Gay ex Laharpe +
7 cm70 mm <br />0.07 m <br /> (22 cm220 mm <br />0.22 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
ascending +  and erect +
terete +, involute +  and flat +
erect;ascending +
straw-colored +
Canada rush +
St. Pierre and Miquelon +, Man. +, N.B. +, Nfld. and Labr. (Nfld.) +, N.S. +, Ont. +, Oreg. +, P.E.I. +, Que. +, Ala. +, Ark. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, Nebr. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Vt. +, Va. +, W.Va. +  and Wis. +
0–200 m +
arranged +  and cluster +
headlike +
Salt, brackish, and calcareous marshes, acid bogs, roadsides, tidal flats, swamps, patterned fen, lake shores, beaches +
5-50-flowered +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
obconic +  and spheric +
pseudoaxillary +  and terminal +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
0.29 cm2.9 mm <br />0.0029 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
cauline +  and basal +
3 +  and 1 +
0.27 cm2.7 mm <br />0.0027 m <br /> (0.38 cm3.8 mm <br />0.0038 m <br />) +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
chestnut-brown +
proximal +  and exserted +
acute;lanceoloid +
0.33 cm3.3 mm <br />0.0033 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
green;brown or purplish black +
persistent +
Fruiting mid summer–fall. +
parietal +  and axile +
in J. J. C. de Laharpe,Essai Monogr. Jonc. +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
tailed;fusiform +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.19 cm1.9 mm <br />0.0019 m <br />) +
green;brown or purplish black +
persistent +
Illustrated +  and Endemic +
generally longer +
Juncus canadensis var. longicaudatus +, Juncus canadensis var. sparsiflorus +, Juncus longicaudatus +  and Juncus polycephalus var. paradoxus +
Juncus canadensis +
Juncus subg. Septati +
species +
straw-colored +  and reddish-brown +
lanceolate +
whitish translucent +
herb +  and cespitose +