Soft Rush - Juncus effusus
Other Names:
Common Rush,
Juncus pylaei, Juncus communis
Non-native Species
Global Rank:
G5
State Rank:
SNA
(see State Rank Reason below)
C-value:
6
Agency Status
USFWS:
USFS:
BLM:
External Links
State Rank Reason (see State Rank above)
Plants in Montana are Juncus effuses ssp. effusus. This subspecies is an aggressive introduced species from Europe, and has colonized in British Columbia and Idaho (Zika 2003).
Short-rhizomatous, caespitose. Stems erect, terete, hollow, 40–100 cm. Leaves mainly basal; blades reduced to a bristle; auricles absent; sheaths purple to brown. Inflorescence open or congested with numerous, pedicellate flowers; bract terete, erect, appearing like a continuation of the stem. Flowers with prophylls; tepals brown with green midvein, 2–3 mm long, acuminate; stamens 3. Capsules ca. 2 mm long, truncate on top; seeds apiculate (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
Our plants are subspecies
effusus, which is introduced from Europe.
J. effusus ssp.
effusus is distinguished by thin, green, symmetrical upper sheaths that are less than 14 centimeters long and have overlapping margins in the upper third. Also, this subspecies has spreading tepals (Zika 2003). See Zika 2003 for comparative illustrations and a key.