Flora of the Hawaiian Islands
Monocotyledon Literature for Juncus effusus
Wagner et al., 1990, 1999.
   Juncaceae -- The Rush Family Bibliography
      Juncus effusus

Common name(s): bog rush, rush, Japanese mat rush
General Information
DistributionWidely distributed in temperate regions of both hemispheres.In the Hawaiian Islands, naturalized on Kaua`i, O`ahu, Moloka`i, Maui, Hawai`i.

Juncaceae - Juncus effusus

Perennial herbs, rhizomes stout, covered with overlapping scales, roots thick; stems crowded along rhizome, reddish brown to purple at base, striate, terete, 4-8 dm long, pith solid.
Leaves basal, scale-like, bladeless, sheaths dark reddish brown to purple at base, paler toward apex.
Flowers numerous in usually contracted or sometimes more open, cymose inflorescences up to 8 cm long, appearing lateral, lowest bract terete, appearing to be a continuation of the stem, bracteoles 3, colorless, ca. 1/4 as long as perianth; perianth parts pale, rigid, narrow, not obscuring the capsule, outer ones ca. 2.5 mm long, inner ones ca. 2 mm long, about as long as capsule, apex long-acuminate; stamens 3; anthers and filaments about equal.
Capsules pale to medium brown, in contrast to the pale perianth, shiny, 3-celled, ovoid, apex truncate.
Seeds pale brown, ca. 0.5 mm long, ca. 3 times longer than wide.
2n = 40, 42, 80