Juncus acuminatus

Michaux

Flora Boreali-Americana 1: 192. 1803.

Common names: Sharp-fruited rush
Illustrated
Synonyms: Juncus acuminatus var. legitimus Engelmann Juncus pallescens A. W. Wood Juncus pondii
Treatment appears in FNA Volume 22.

Herbs, perennial, cespitose, not rhizomatous, 1.4–10 dm. Culms erect, terete, 1–3 mm diam., smooth. Cataphylls 1–2, gray, apex acute. Leaves: basal 1–2, cauline 1–2; auricles 1–1.5 mm, apex rounded, scarious; blade green, straw-colored, or pink, nearly terete, 1–40 cm. Inflorescences terminal panicles of 5–50 heads, 5–15 cm, branches ascending; primary bract erect; heads (2–) 5–20 (–50) -flowered, hemispheric (to spheric), 3–10 mm diam. Flowers: tepals light-brown to greenish, lanceolate, 2.6–3.5 (–3.9) mm, apex acuminate; stamens 3 (or 6), anthers 1/3 filament length. Capsules equaling perianth or slightly exserted, straw-colored, 1-locular, ellipsoid to narrowly ovoid, 2.8–3.5 (–4) mm, apex acute, valves separating at dehiscence, fertile throughout or only proximal to middle. Seeds ellipsoid to oblong, 0.3–0.4 mm, not tailed; body clear yellowbrown. 2n = 40.


Phenology: Fruiting early summer–fall.
Habitat: Shores, swamps, ditches, springs, wet meadows, and rock outcrops
Elevation: 0–2200 m

Distribution

V22 301-distribution-map.jpg

B.C., N.S., Ont., Que., Ala., 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., N.H., N.J., N.Mex., N.Y., N.C., Ohio., Okla., Oreg., Pa., R.I., S.C., Tenn., Tex., Vt., Va., Wash., W.Va., Wis., Mexico, Central America (Honduras)

Discussion

Selected References

None.

Lower Taxa

None.
... more about "Juncus acuminatus"
persistent +
acute +, acuminate +  and rounded +
scarious +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
Ralph E. Brooks* +  and Steven E. Clemants* +
Michaux +
pink +, straw-colored +  and green +
1 cm10 mm <br />0.01 m <br /> (40 cm400 mm <br />0.4 m <br />) +
clear yellowbrown +
ascending +  and erect +
terete +, involute +  and flat +
Sharp-fruited rush +
B.C. +, N.S. +, Ont. +, Que. +, Ala. +, 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. +, N.H. +, N.J. +, N.Mex. +, N.Y. +, N.C. +, Ohio. +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, Wash. +, W.Va. +, Wis. +, Mexico +  and Central America (Honduras) +
0–2200 m +
arranged +  and cluster +
headlike +
Shores, swamps, ditches, springs, wet meadows, and rock outcrops +
(2-)5-20(-50)-flowered +
0.3 cm3 mm <br />0.003 m <br /> (1 cm10 mm <br />0.01 m <br />) +
hemispheric +
pseudoaxillary +  and terminal +
cauline +  and basal +
3 +  and 1 +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
straw-colored +
ellipsoid;narrowly ovoid +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
green;brown or purplish black +
persistent +
Fruiting early summer–fall. +
parietal +  and axile +
Flora Boreali-Americana +
not tailed;ellipsoid;oblong +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
green;brown or purplish black +
persistent +
Illustrated +
generally longer +
Juncus acuminatus var. legitimus +, Juncus pallescens +  and Juncus pondii +
Juncus acuminatus +
Juncus subg. Septati +
species +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.39 cm3.9 mm <br />0.0039 m <br />) +
light-brown +  and greenish +
lanceolate +
0.26 cm2.6 mm <br />0.0026 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
only proximal;middle +
herb +  and cespitose +