Slender Rush (Juncus tenuis)

Family:

Rush Family (Juncaceae)

Other Names:

field rush, path grass, path rush, poverty rush, slender yard rush, wire grass, yard rush.

Origin and Distribution:

Slender rush is a native of North America and is widespread across the U.S. and Canada. This rush is scattered throughout Ohio, slightly more common in the north and northeast regions. It thrives in both dry and wet soils of pastures, meadows, roadsides and waste places. Some of its common names stem from the fact that it also grows abundantly in compacted soils along paths.

Plant Description:

Slender rush is a clump-forming, grass- or sedge-like perennial, characterized by its wiry dark green stems and terminal clusters of greenish-brown flowers. This species reproduces by seeds.

  • Root System:

    The roots are fibrous. Plants sometime produce short rhizomes (horizontal underground stems).

  • Stems:

    Slender rush has erect, wiry, rounded, hollow, dark green stems that grow 4 to 24 inches tall.

  • Leaves:

    Narrow, grass-like leaves are produced along the lower portion of the stem. The leaf blade (free part of the leaf) is half as long as to longer than the stem, and can be flat or have inwardly rolled edges. The leaf sheaths (part of the leaf surrounding the stem) have whitish, membranous margins, and cover the lower half of the stem. The sheath margins extend upward beyond the top of the sheath to form a pair of whitish, membranous, rounded, flap-like appendages (auricles) (1/25 to 1/6 inch long).

  • Flowers:

    Small, greenish-brown flowers are clustered near the tips of branches in a flat-topped, branched flower head. Branches can be 1/3 to 3 inches long. Each flower has 3 scale-like petals and 3 sepals (modified leaves directly below the petals). A pair of narrow, curly, modified leaves (bracts) (1/3 to 4 inches long) usually extends above the flower head.

  • Fruits and Seeds:

    Seed pods are egg-shaped, brown and divided into 3 sections, each section containing several seeds. Six scale-like, pointed bracts (modified leaves) surround each seed pod. Seeds are very small (about 1/8 inch long), translucent, orangish-brown, and sometimes winged along one side.

Similar Species:

Slender rush may be confused with both grasses and sedges, but it can be distinguished by its round stem, flowers that consist of petals and sepals, and its many-seeded seed pod which is surrounded by 6 pointed bracts.

Biology:

Flowering occurs between June and August. Control of slender rush populations may be aided by plowing the infested area, then seeding with a cultivated crop. If the area cannot be cultivated, it could be fertilized, harrowed, and seeded with a mixture containing white clover.

Toxicity:

None known.

Facts and Folklore:

  • There are 3 varieties of slender rush in Ohio.