- You are here:
- Dichotomous Key
- Asteraceae
- Asteraceae Group 2
- Symphyotrichum
- Symphyotrichum boreale
Symphyotrichum boreale — rush American-aster
Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.
Facts
Rush American-aster is found in high-pH fens and marshes in northern North America, including Maine, New Hampshire and Vermont. This species has distinctively long and very narrow leaves, often with revolute margins.
Habitat
Fens
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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- Leaf type
- leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- basal: the leaves are growing only at the base of the plant
- Leaf blade edges
-
- the edge of the leaf blade has no teeth or lobes
- the edge of the leaf blade has teeth
- Flower type in flower heads
- the flower head has tubular disk flowers in the center and ray flowers, these often strap-shaped, around the periphery
- Ray flower color
- blue to purple
- Tuft or plume on fruit
- at least a part of the plume is made up of fine bristles
- Spines on plant
- the plant has no spines
- Leaf blade length
- 15–150 mm
- Disk flower number
-
- 11-20
- 21-50
-
Flowers
- Bases of bract appendages
- NA
- Bract color
- the bracts are colored, or at least tinged with, pink, red or purple
- Bract cycle number
- there are three or more cycles of bracts
- Bract inner side hairs
- the bracts are not hairy on their inner surfaces
- Bract keels
- the bracts do not have keels
- Bract margins
- there are fine hairs along the bract margins
- Bract outer side hair type
- the bracts are not hairy on their outer surface
- Bract outer side hairs
- the bracts are not hairy on their outer surfaces
- Bract separation
- the bracts appear completely unconnected to one another on all flower heads
- Bract shape
-
- the main bracts are lanceolate (widest above the base, then taper narrowly towards the tip)
- the main bracts are linear (long and very narrow)
- the main bracts are oblong (roughly rectangular but rounded at the ends)
- Bract spines
- the bracts have no spines
- Bract texture
-
- the bracts appear leathery or hardened
- the bracts appear thin, flexible and nearly translucent
- the bracts have a similar texture to a leaf
- Bract tip color
- the tips are a different color from the center of the bract
- Bract tip extension appearance
- NA
- Bract tip extension edge
- there are no projections from the bract tips
- Bract tip orientation
-
- the bracts are pressed against the plant, or spreading out at the tips
- the tips of the bracts curve outwards and downwards from the plant
- Bract tip shape
-
- the tips of the bracts acute (have a sharp point)
- the tips of the bracts are acuminate (tapered to a narrow point)
- Bracts
- the bracts in separate cycles are similar or gradually changing from the outer to inner cycles
- Disk flower color
-
- blue to purple
- green to brown
- pink to red
- yellow
- Disk flower lobe number
- 5
- Disk flower number
-
- 11-20
- 21-50
- Disk flower proportions
-
- 0-15%
- 16-30%
- Disk flower reproductive parts
- the disk flower has both pollen- and seed-producing parts
- Disk flower shape
- the disk flower is tube-shaped (cylindrical), or gradually widening like a funnel
- Flower head number
- each flowering stem has four or more flower heads on it
- Flower head outer flowers
- at the outer edge of the flower head, each flower has a single enlarged lobe or strap
- Flower head platform
- the base has no bristles or papery scales
- Flower head platform surface
- NA
- Flower head position
- some or all the flower heads are grouped in clusters of two or more
- Flower head profile
-
- the disk is flat or nearly flat across the top
- the disk is rounded across the top
- Flower head shape
- the sides of the flower head are roughly parallel, like a cylinder
- Flower type in flower heads
- the flower head has tubular disk flowers in the center and ray flowers, these often strap-shaped, around the periphery
- Height of flower head base
- Up to 4 mm
- Inflorescence branching (Solidago)
- NA
- Inflorescence shape
- the inflorescence is not flat-topped but appears rounded, with some flower heads distinctly higher than others
- Inflorescence stem
- the stem of the inflorescence is not hairy
- Ovary attachment
- the ovary is attached at or near the base
- Ovary beak
- there is no beak on the ovary
- Ovary cross-section
- the ovary is compressed (flattened)
- Ovary hair type
- the ovary has hairs on it, but the hairs have no glands
- Ovary hairs
- the ovary has hairs on it
- Ovary lines or ribs
-
- there are four to six lines or ribs visible on the ovary
- there are three lines or ribs visible on the ovary
- Ovary profile
- in profile, the ovary is roughly egg-shaped, but widest above the middle
- Ovary surface
- the ovary surface has no points, bumps or wrinkles, though it may have lines, ribs or wings
- Ovary wing number
- 0
- Peduncle hair type
- NA
- Peduncle hairs
- the peduncles have no hairs
- Peduncle length
- 5–50 mm
- Ray flower color
- blue to purple
- Ray flower reproductive parts
- the ray flowers have carpels or stamens, but not both
- Ray flowers
-
- 16-25
- 26-50
- Ray length
- 7–20 mm
- Reproductive system
- some of the flowers on the plant have only carpels or stamens, while others have both carpels and stamens
- Scale tip
- NA
- Smaller bracts at base of bracts
- there is a cycle of much smaller bracts outside the cycle of larger and longer bracts
- Style branch number
- the style has two branches
- Style branches
- the style branch is narrow at the tip, or the style branches are narrow at the tips
- Width of flower head base
- At least 8 mm
-
Fruits or seeds
- Number of pappus parts
- 11 or more
- Ovary beak length
- 0 mm
- Ovary length in developed fruit
- 0.6–2 mm
- Seed hair tuft bases
- the pappus hairs are not attached to one another near the base
- Seed hair tuft color
- the pappus hairs are white or off-white
- Seed hair tuft details
- the pappus hairs are hooked or barbed
- Seed hair tuft length
- 2.7–6.7 mm
- Seed hair tuft tips
- the pappus hairs are slender
- Seed hairs uniform
- all the pappus hairs are approximately the same length
- Seed tuft scale number
- 0
- Seed tuft type
- the pappus is made of very fine hairs or bristles
- Top of disk flower ovary
- NA
- Tuft or plume on fruit
- at least a part of the plume is made up of fine bristles
-
Glands or sap
- Leaf blade glands
- the leaf blades have no glandular (translucent) dots or scales
- Ovary glands
- there are no visible glands on the ovary
- Sap
- the sap is clear and watery
-
Growth form
- Growth form
- the plant has one or more free-standing stems
- Plant lifespan
- the plant is perennial, it shows evidence of previous year's leaves, stems or stem bases
- Spines on plant
- the plant has no spines
- Underground organs
- the plant has a rhizome (a horizontal underground stem with roots growing from it)
-
Leaves
- Final leaf segment length (compound lvs only)
- 0 mm
- Final leaf segment width (compound lvs only)
- 0 mm
- Hairs on underside of leaf blade
- the underside of the leaf is not hairy, or has very few hairs
- Hairs on upper side of leaf blade
- the upper side of the leaf is not hairy, or has very few hairs
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- basal: the leaves are growing only at the base of the plant
- Leaf blade base
-
- the leaf has no petiole
- the leaf has no petiole and at the base it clasps the stem, or goes all the way around the stem so the stem appears to pierce the leaf
- Leaf blade base shape
- the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
- Leaf blade edges
-
- the edge of the leaf blade has no teeth or lobes
- the edge of the leaf blade has teeth
- Leaf blade flatness
- the edges of the leaf are curled under
- Leaf blade hairs
- NA
- Leaf blade length
- 15–150 mm
- Leaf blade shape
-
- the leaf blade is linear (very narrow with more or less parallel sides)
- the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)
- the leaf blade is oblong (rectangular but with rounded ends)
- the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
- Leaf blade surface colors
- there is no noticeable color variation on the upper surface of the leaf
- Leaf blade tip
-
- the tip of the leaf blade is acuminate (tapers to a long, thin point)
- the tip of the leaf blade is acute (sharply pointed)
- Leaf blade veins
- the leaf blade has one main vein running from the base towards the tip
- Leaf blade width
- 2–9 mm
- Leaf disposition
- the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
- Leaf spines
- there are no spines on the leaf edges
- Leaf stalk
- the leaves have no leaf stalks, but attach directly to the stem
- Leaf stalk length
- 0 mm
- Leaf tip extension
- NA
- Leaf tufts in axils
- there are no clusters of smaller leaves
- Leaf type
- leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaflet number
- 0
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
-
Place
- Habitat
- wetlands
- New England state
-
- Maine
- New Hampshire
- Vermont
- Specific habitat
- fens
-
Stem, shoot, branch
- Flowering stem cross-section
- the flowering stem is circular, or with lots of small angles
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Stem bloom
- the stem has a powdery or waxy film on it that can be rubbed away
- Stem internode hair direction
- NA
- Stem internode hair type
- the stem has no hairs between the nodes
- Stem internode hairs
- the stem has no hairs between the nodes
- Stem wings
- the stem does not have wings on it
Wetland status
Occurs only in wetlands. (Wetland indicator code: OBL)
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.
- Maine
- fairly widespread (S-rank: S4)
- New Hampshire
- unrankable (S-rank: SU), Ind (code: Ind)
- Vermont
- historical (S-rank: SH)
From Flora Novae Angliae dichotomous key
2. Symphyotrichum boreale (Torr. & Gray) A. & D. Löve N
rush American-aster. Aster borealis (Torr. & Gray) Prov.; A. junciformis Rydb. • ME, NH, VT. Circumneutral fens. The report of this species in MA (e.g., Sorrie and Somers 1999) is based on a collection of Symphyotrichum novi-belgii var. elodes—Goodale et al. 69563 ( MASS!).
Native to North America?
Yes
Sometimes confused with
- Symphyotrichum anticostense:
- leaf blades usually narrow-lanceolate, with plane margins, 5–25 mm wide, base of stem thicker than 2.5 mm, and plants mostly of river shores (vs. S. boreale, with leaf blades linear to oblong-linear, often with revolute margins, mostly 2–5 mm wide, base of stem thinner than 2.5 mm, and plants mostly of high-pH fens).
Synonyms
- Aster borealis (Torr. & Gray) Prov.
- Aster junciformis Rydb.