Juncus conglomeratus — bunch-flowered soft rush
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Facts
Bunch-flowered soft rush is considered introduced in New England, where it is found in open wetlands in Connecticut. It is easily confused with common soft rush (Juncus effusus).
Habitat
Bogs, fens, marshes, meadows and fields, swamps, wetland margins (edges of wetlands)
New England distribution
Adapted from BONAP data
Native: indigenous.
Non-native: introduced (intentionally or unintentionally); has become naturalized.
County documented: documented to exist in the county by evidence (herbarium specimen, photograph). Also covers those considered historical (not seen in 20 years).
State documented: documented to exist in the state, but not documented to a county within the state. Also covers those considered historical (not seen in 20 years).
Note: when native and non-native populations both exist in a county, only native status is shown on the map.
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enlargeCharacteristics
- Habitat
- wetlands
- New England state
-
- Connecticut
- Maine
- New Hampshire
- Rhode Island
- 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
-
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
- 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 crowded together in one tight cluster
- 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
- 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
- the capsule is shorter than the 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
- Underground organs
- the plant has a rhizome (a horizontal underground stem with roots growing from it)
-
Leaves
- Auricle length
- 0 mm
- Auricle texture
- 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
- Width of seed-producing inflorescence
- 10–25 mm
-
Place
- Habitat
- wetlands
- New England state
-
- Connecticut
- Maine
- New Hampshire
- Rhode Island
- Specific habitat
-
- bogs
- edges of wetlands
- fens
- marshes
- meadows or fields
- swamps
-
Stem, shoot, branch
- Plant height
- 40–130 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
Not classified
In New England
Distribution
- Connecticut
- absent
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- absent
Conservation status
None
From Flora Novae Angliae dichotomous key
14. Juncus conglomeratus L. E
bunch-flowered soft rush. Juncus effusus L. var. conglomeratus (L.) Engelm. • CT, ME, NH, RI. Open wetlands, sometimes with a history of human disturbance.
Native to North America?
No
Sometimes confused with
- Juncus pylaei:
- involucral bract not swollen, erect in fruit, leaf sheaths with dark red-brown to purple-black bases, the upper ones 5–12 cm long, and stems with 10–20 longitudinal ridges (vs. J. conglomeratus, with the involucral bract swollen at the base of the inflorescence, sometimes somewhat reflexed in fruit, leaf sheaths with red-brown bases, the upper ones 15–23 cm long, and stems with 12–30 longitudinal ridges).
- Juncus effusus:
- apical portion of stem relatively lustrous, smooth or nearly so below the inflorescence, with usually 30–60 longitudinal striations that are inconspicuous until drying (vs. J. conglomeratus, with the apical portion of stem relatively dull, evidently ridged below the inflorescence with 12–30 longitudinal grooves).
Synonyms
- Juncus effusus L. var. conglomeratus (L.) Engelm.