Juncus effusus L.
common rush
Juncaceae (Rush family)

Introduction to Vascular Plants


© Jamie Fenneman     (Photo ID #4188)


E-Flora BC Static Map

Distribution of Juncus effusus
Click here to view the full interactive map and legend

Species Information

Perennial, strongly tufted herb in large, dense clusters from compact rhizomes; stems smooth or finely lined with 30 to 60 longitudinal ridges, 30-120 cm tall.
Reduced to short sheaths at the base of the stem.
Inflorescence with numerous flowers and branches, 3-12 cm long, appearing as if on the side of the stem; perianth segments green or light brown, 3-6 mm long, pointed, subequal; stamens 3; anthers about as long as the filaments; involucral bract 5-25 cm long, cylindrical, resembling a continuation of the stem, smooth or finely lined with 30 to 60 longitudinal ridges.
Capsules, egg-shaped, rounded on the tops, slightly shorter than the perianth segments; seeds ellipsoid, 0.5 mm long, lacking tail-like appendages.
Variable species with several varieties recognized in our area

1. Perianth segments greenish with little or no brownish borders, stiff when dry...................... var. pacificus Fern. & Wieg.

1. Perianth segments deep brown with green midribs, soft when dry.

2. Uppermost sheaths closed, leathery, lustrous, and chestnut brown throughout........................ var. gracilis Hook.

2. Uppermost sheaths looser, membranaceous, dull greenish-brown above............................ var. brunneus Engelm.

SourceThe Illustrated Flora of British Columbia

USDA Species Characteristics

Flower Colour:
Blooming Period:
Fruit/Seed characteristics:
Colour: Yellow
Present from Summer to Fall
Source:  The USDA


Ecological Framework for Juncus effusus

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
122 0 1805
Slope Gradient (%)
6 0 120

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

189 0 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
5 1 8
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

CDF(7), CWH(79), ESSF(1), ICH(2), SBS(2)

Habitat and Range

Moist to wet disturbed places, pastures, fields, ditches, clearings, forest margins, marshes and peat bogs in the lowland, steppe, and montane zones; common W of the Coast-Cascade Mountains; N to AK and S to MT, ID, AZ and CA; Eurasia.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Juncus effusus var. subconglomeratus