Ageratina aromatica (L.) Spach

lesser snakeroot

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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

Lesser snakeroot is a plant of dry forest gaps and slopes, and the trend of increasing forest canopy in New England may be a factor in the decreasing occurrence of this plant. It is currently found in a few locations in Connecticut, Massachusetts and Rhode Island.

Habitat

Forests, talus and rocky slopes

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Massachusetts
  • Rhode Island
Leaf type
leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
Leaf arrangement
opposite: there are two leaves per node along the stem
Leaf blade edges
the edge of the leaf blade has teeth
Flower type in flower heads
the flower head has disk flowers only, and lacks the strap-shaped flowers
Ray flower color
NA
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
20–90 mm
Disk flower number
  • 11-20
  • 6-10
Show All Characteristics
  • Flowers
    Bases of bract appendages
    NA
    Bract color
    the bracts are not colored or tinged with pink, red or purple
    Bract cycle number
    • there are three or more cycles of bracts
    • there are two main cycles of bracts
    Bract outer side hair type
    the bracts are hairy, with simple hairs on their outer surface
    Bract outer side hairs
    the bracts are hairy on their outer surfaces
    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)
    Bract spines
    the bracts have no spines
    Bract texture
    the bracts have a similar texture to a leaf
    Bract tip color
    the tips are the same color as the center of the bract
    Bract tip extension appearance
    NA
    Bract tip extension edge
    NA
    Bract tip shape
    the tips of the bracts acute (have a sharp point)
    Bracts
    the bracts in separate cycles are similar or gradually changing from the outer to inner cycles
    Disk flower color
    white
    Disk flower number
    • 11-20
    • 6-10
    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, the flowers have no enlarged lobe or strap, and are of similar size as those in the center of the disk
    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 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 disk flowers only, and lacks the strap-shaped flowers
    Height of flower head base
    3.5–5 mm
    Inflorescence branching (Solidago)
    NA
    Inflorescence shape
    the inflorescence is flat-topped in profile
    Inflorescence stem
    hairs are present on the stem of the inflorescence
    Number of bracts at flower head base
    8–30
    Ovary cross-section
    the ovary has five or more corners in cross-section
    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
    Peduncle hair type
    the hairs on the peduncles are simple (not branched), don’t have glands, and are not woolly
    Peduncle hairs
    the peduncles are hairy
    Peduncle length
    2–9 mm
    Ray flower color
    NA
    Ray flower reproductive parts
    NA
    Ray flowers
    0
    Ray length
    0 mm
    Reproductive system
    all the flowers on the plant contain 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
    • the style branch is wider at the tip and has a flattened end, or the style branches are wider at the tips and have flattened ends
    Width of flower head base
    3–6 mm
  • Fruits or seeds
    Number of pappus parts
    • 10
    • 11 or more
    • 5
    • 6
    • 7
    • 8
    • 9
    Ovary length in developed fruit
    2.1–3.3 mm
    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
    3–4 mm
    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
    Ovary glands
    there are glands on the ovary surface
    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
  • 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 fuzzy or hairy
    Hairs on upper side of leaf blade
    the upper side of the leaf is fuzzy or hairy
    Leaf arrangement
    opposite: there are two leaves per node along the stem
    Leaf blade base
    the leaf has a distinct petiole
    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
    • the base of the leaf blade is rounded
    • the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)
    • the base of the leaf is cordate (heart-shaped) or sagittate (arrow-shaped)
    Leaf blade edges
    the edge of the leaf blade has teeth
    Leaf blade hairs
    the leaf blade has simple hairs with no glands, and not tangled or wooly
    Leaf blade length
    20–90 mm
    Leaf blade shape
    • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
    • the leaf blade is triangular, with the stalk or attachment point on one of the sides
    Leaf blade tip
    • the tip of the leaf blade is acute (sharply pointed)
    • the tip of the leaf blade is obtuse (bluntly pointed)
    Leaf blade veins
    the leaf blade has three main veins running from the base towards the tip
    Leaf blade width
    15–40 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 leaf stalks
    Leaf stalk length
    1–12 mm
    Leaf tip extension
    NA
    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
    terrestrial
    New England state
    • Connecticut
    • Massachusetts
    • Rhode Island
    Specific habitat
    • forests
    • talus or rocky slopes
  • Scent
    Plant odor
    the plant has a pleasant odor, such as licorice, fruit or resin
  • Stem, shoot, branch
    Leaves on stem
    there is at least one full leaf above the base of the flowering stem
    Stem internode hair direction
    the hairs point mostly upwards to outwards
    Stem internode hair type
    the hairs on the stem are plain, without glands or branches, and not tangled
    Stem internode hairs
    the stem has hairs between the nodes

Wetland Status

Not classified

New England Distribution and Conservation Status

Distribution

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

Conservation Status

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

Connecticut
extremely rare (S-rank: S1), endangered (code: E)
Massachusetts
extremely rare (S-rank: S1), endangered (code: E)
Rhode Island
historical (S-rank: SH), state historical (code: SH)

var. aromatica

Massachusetts
unranked (S-rank: SNR)

Native to North America?

Yes

Sometimes Confused With

Ageratina altissima:
leaf blades herbaceous, mostly 6-18 cm long, short-acuminate to acuminate at the apex, with 9-25 well developed teeth per margin, and petioles mostly 20-80 mm long on well developed leaves (vs. A. aromatica, with leaf blades firm, mostly 3-7 cm long, obtuse to acute at the apex, with 7-12 well developed teeth per margin, and petioles mostly 1-15 mm long).

Synonyms

  • Eupatorium aromaticum L.

Family

Asteraceae

Genus

Ageratina

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Information from Dichotomous Key of Flora Novae Angliae

2.  Ageratina aromatica (L.) Spach NC

lesser snakeroot. Eupatorium aromaticum L. • CT, MA, RI. Dry-mesic to mesic, often rocky, forests and forested slopes.