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- Ageratina aromatica
Ageratina aromatica — lesser snakeroot
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Facts
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
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
- 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
-
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
In New England
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)
From Flora Novae Angliae dichotomous key
2. Ageratina aromatica (L.) Spach NC
lesser snakeroot. Eupatorium aromaticum L. • CT, MA, RI. Dry-mesic to mesic, often rocky, forests and forested slopes.
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.