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Juncus effusus — common soft rush

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New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Facts

There are two subspecies of common soft rush in New England. One of them is native and found in all New England states, while the other is introduced, and found only in Massachusetts, Maine and Rhode Island. Various Native American peoples used common soft rush for tying, binding and weaving.

Habitat

Anthropogenic (man-made or disturbed habitats), marshes, meadows and fields, shores of rivers or lakes, wetland margins (edges of wetlands)

Characteristics

Habitat
  • aquatic
  • terrestrial
  • wetlands
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Stem shape in cross-section
the stem is round or oval in cross-section
Leaf blade width
0 mm
Leaf blade cross-section
NA
Inflorescence position
the inflorescence appears to come from the side of the plant because the involucral bract at its base looks like an extension of the main stem
Inflorescence branching
the inflorescence is branched
Fruit type (general)
the fruit is a capsule, with at least three seeds in it
Fruit length
1.5–3.2 mm
Leaf position on plant
the attachment points of all the leaves are at or near the base of the plant
Perianth composition
the perianth is green or brown, with six sepal-like parts, and a leafy texture
Fruit cross-section
the fruit is triangular to terete (circular) in cross-section
Show all characteristics

  • Flowers

    Anther color (dry)
    the anthers range in color from white to tan or yellow to yellow-brown
    Anther length
    0.5–0.8 mm
    Floral bristle color
    NA
    Floral bristle number
    NA
    Floral bristle relative length
    NA
    Floral bristles
    NA
    Floral scale hairs
    NA
    Floral scale length
    0 mm
    Floral scale nerves
    NA
    Flower number per cluster
    • 5-20
    • more than 20
    Inflorescence bract angle
    the bracts are vertical or angled only slightly outwards
    Inflorescence bract number
    there is just one bract on the inflorescence
    Inflorescence bract position (Sparganium)
    NA
    Inflorescence bracts
    there is only one bract, and it looks like a continuation of the stem
    Inflorescence branching
    the inflorescence is branched
    Inflorescence crowding
    the inflorescence is at least somewhat spread out, with at least one branch coming from the main stem
    Inflorescence position
    the inflorescence appears to come from the side of the plant because the involucral bract at its base looks like an extension of the main stem
    Inflorescence shape
    the aggregations within the inflorescence are roughly circular (not flattened) in cross-section
    Inflorescence type
    there are two or more flowers, spikes or flower clusters on a branched inflorescence
    Perianth composition
    the perianth is green or brown, with six sepal-like parts, and a leafy texture
    Stamen length
    1–1.6 mm
    Stamen number
    3
    Stigma number
    3
    Style division
    the style is divided nearly from the base
    floral bristle barbs
    NA

  • Fruits or seeds

    Achene beak length
    0 mm
    Achene surface texture
    NA
    Achene tubercle relative width
    NA
    Achene tubercle width
    0 mm
    Capsule relative length
    • the capsule is about equal to the perianth
    • the capsule is longer thant he perianth
    Fruit cross-section
    the fruit is triangular to terete (circular) in cross-section
    Fruit length
    1.5–3.2 mm
    Fruit type (general)
    the fruit is a capsule, with at least three seeds in it
    Fruit type (specific)
    the fruit is a capsule (splits along two or more seams, apical teeth or pores when dry, to release two or more seeds)
    Locules in capsule
    the capsule has three locules
    Seed length
    0.3–0.5 mm
    Seed tail relative length
    0.3–0.5 mm
    Seed tails
    there is no tail on the seeds
    Tubercle height
    0 mm

  • Growth form

    Lifespan
    the plant lives more than two years
    Rhizome thickness
    2–4 mm
    Underground organs
    the plant has a rhizome (a horizontal underground stem with roots growing from it)

  • Leaves

    Auricle length
    0 mm
    Auricle texture
    NA
    Auricles
    NA
    Leaf blade cross-section
    NA
    Leaf blade length
    0 mm
    Leaf blade width
    0 mm
    Leaf form
    all the leaves hold their form out of water
    Leaf position on plant
    the attachment points of all the leaves are at or near the base of the plant
    Leaf septa
    NA
    Leaf sheath hairs
    the leaf sheathes are without hairs
    Pedicel length (Typha)
    0 mm
    Stem leaf blade ligules
    NA
    Stem leaf blades
    there are no leaves on the main stem, or there is a small tooth or tiny blade, or a leaf sheath with no blade

  • Place

    Habitat
    • aquatic
    • terrestrial
    • wetlands
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • edges of wetlands
    • man-made or disturbed habitats
    • marshes
    • meadows or fields
    • shores of rivers or lakes

  • Stem, shoot, branch

    Plant height
    50–130 cm
    Stem shape in cross-section
    the stem is round or oval in cross-section
    Stem texture near tip
    the stem feels smooth near the tip
    Stem thickness at midpoint
    1–2.5 mm

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England distribution and conservation status

Distribution

Connecticut
present
Maine
present
Massachusetts
present
New Hampshire
present
Rhode Island
present
Vermont
present

Conservation status

Exact status definitions can vary from state to state. For details, please check with your state.

ssp. effusus

Massachusetts
not applicable (S-rank: SNA)

var. solutus

Massachusetts
widespread (S-rank: S5)

Native to North America?

Yes and no (some introduced)

Sometimes confused with

Juncus conglomeratus:
apical portion of stem relatively dull, evidently ridged below the inflorescence with 12–30 longitudinal grooves (vs. J. effusus, with the apical portion of stem relatively lustrous, smooth or nearly so below the inflorescence, with usually 30–60 longitudinal striations that are inconspicuous until drying).
Juncus pylaei:
apical portion of stem relatively dull, evidently ridged below the inflorescence with 12–30 longitudinal grooves (vs. J. effusus, with the apical portion of stem relatively lustrous, smooth or nearly so below the inflorescence, with usually 30–60 longitudinal striations that are inconspicuous until drying).).

Synonyms

  • Juncus effusus var. solutus Fern. & Wieg.

Family

Juncaceae

Genus

Juncus

Notes on subspecies and varieties in New England

Juncus effusus L. ssp. effusus is known from MA, ME, RI and is introduced.J. effusus ssp. solutus (Fern. & Wieg.) Hämet-Ahti is known from CT, MA, ME, NH, RI, VT, and is native to New England.

Help

From the dichotomous key of Flora Novae Angliae

19.  Juncus effusus L. n

common soft rush.  19a. Juncus effusus L. var. solutus Fern. & Wieg.;  19b. Juncus effusus L. var. compactus Lej. & Court. • CT, MA, ME, NH, RI, VT. Graminoid marshes, ditches, shorelines, meadows, low areas in fields. Juncus effusus has been treated variously by different authors, most commonly as being comprised of several varieties. However, some recent treatments (Brooks and Clemants 2000) abandon recognition of any infraspecific taxa. Unfortunately, this approach conceals a great deal of variation in (and understanding of) this complex. Treatment of this species complex follows the work of Hämet-Ahti (1980; considered appropriate by Snogerup et al. 2002). See also J. conglomeratus and J. pylaei, traditionally considered as infraspecific taxa of J. effusus (here treated as separate species).

1a.  Tepals ascending or appressed to the capsule [Fig. 147]; leaf sheaths on reproductive stems (12–) 15–27 cm long, usually loose and not clasping the stem (sometimes even unrolled), with margins overlapping only in the basal half (if at all), usually lacking a dark, marginal band

… 19a. J. effusus ssp. solutus (Fern. & Wieg.) Hämet-Ahti

1b.  Tepals spreading from the base in fruit; leaf sheaths on reproductive stems 6–14 cm long, usually clasping the stem, with margins overlapping except for the apical 2–4 cm, usually with a dark, marginal band … 19b. J. effusus ssp. effusus

Subspecies solutus is native to New England and known from CT, MA, ME, NH, RI, VT. 
Subspecies effusus is introduced and is known from MA, ME, RI. The latter subspecies varies 
in the congestion of its flowers (i.e., from tightly compact to open inflorescences).