Juncus trifidus L.

highland 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 About

In North America, highland rush is mostly limited to New England mountains and the eastern edge of Canada. In New England it is found in boreal and alpine cliffs, ridges and plateaus above treeline.

Habitat

Alpine or subalpine zones, cliffs, balds, or ledges, mountain summits and plateaus, ridges or ledges

Characteristics

Habitat
terrestrial
New England state
  • Maine
  • New Hampshire
  • Vermont
Stem shape in cross-section
the stem is round or oval in cross-section
Leaf blade width
0.5–1 mm
Leaf blade cross-section
the leaf blade is flat or rolled in at the edges
Inflorescence position
the inflorescence is at the tip of the plant
Inflorescence branching
the inflorescence is branched
Fruit type (general)
the fruit is a capsule, with at least three seeds in it
Fruit length
2.2–3.5 mm
Leaf position on plant
some leaf attachment points are above the midpoint of the stem
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
    1.2–1.5 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
    • 1
    • 2-5
    Inflorescence bract angle
    the bracts are vertical or angled only slightly outwards
    Inflorescence bract number
    there are two to five bracts per inflorescence
    Inflorescence bract position (Sparganium)
    NA
    Inflorescence bracts
    there are at least two bracts, and they are either flat or folded or rolled in at the edges
    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 is at the tip of the plant
    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
    1.7–2 mm
    Stamen number
    4-6
    Stigma number
    3
    Style division
    the top two thirds of the style is divided
    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
    Fruit cross-section
    the fruit is triangular to terete (circular) in cross-section
    Fruit length
    2.2–3.5 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 one locule
    Seed length
    0.9–1.3 mm
    Seed tail relative length
    0.9–1.3 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
    0.5–0.8 mm
    Underground organs
    the plant has a rhizome (a horizontal underground stem with roots growing from it)
  • Leaves
    Auricle length
    Up to 4 mm
    Auricle texture
    the auricles are weak, papery and translucent
    Auricles
    the leaf sheath has auricles on it
    Leaf blade cross-section
    the leaf blade is flat or rolled in at the edges
    Leaf blade length
    50–120 mm
    Leaf blade width
    0.5–1 mm
    Leaf form
    all the leaves hold their form out of water
    Leaf position on plant
    some leaf attachment points are above the midpoint of the stem
    Leaf septa
    the leaf blades do not have transverse septa
    Leaf sheath hairs
    the leaf sheathes are without hairs
    Pedicel length (Typha)
    0 mm
    Stem leaf blade ligules
    there are no ligules at the leaf blade bases
    Stem leaf blades
    there are fully-developed leaves with leaf blades on the main stem
    Width of seed-producing inflorescence
    2–5 mm
  • Place
    Habitat
    terrestrial
    New England state
    • Maine
    • New Hampshire
    • Vermont
    Specific habitat
    • alpine or subalpine zones
    • cliffs, balds, or ledges
    • mountain summits and plateaus
    • ridges or ledges
  • Stem, shoot, branch
    Plant height
    10–40 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
    0.3–0.6 mm

Wetland Status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

New England Distribution and Conservation Status

Distribution

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

Conservation Status

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

Maine
uncommon to fairly widespread (S-rank: S3S4)
New Hampshire
uncommon (S-rank: S3), W (code: W)
Vermont
extremely rare to rare (S-rank: S1S2)

Native to North America?

Yes

Synonyms

  • Juncus trifidus ssp. carolinianus Hämet-Ahti
  • Juncus trifidus var. monanthos (Jacq.) Bluff ex Fingerhuth

Family

Juncaceae

Genus

Juncus

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Information from Dichotomous Key of Flora Novae Angliae

37.  Juncus trifidus L. N

highland rush. Juncus trifidus L. ssp. carolinianus Hämet-Ahti; J. trifidus L. var. monanthos (Jacq.) Bluff ex Fingerhuth • ME, NH, VT. Boreal and alpine cliffs, ridges and plateaus above treeline, rarely weedy along trails just below treeline.