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- Juncus trifidus
Juncus trifidus — highland rush
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Facts
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
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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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
-
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)
In New England
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.
- Vermont
- extremely rare (S-rank: S1)
From Flora Novae Angliae dichotomous key
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.