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- Eupatorium pubescens
Eupatorium pubescens — hairy boneset, hairy thoroughwort
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Facts
Hairy thoroughwort is thought to be derived from a hybrid of round-leaved thoroughwort (Eupatorium rotundifolium) and upland thoroughwort (E. sessilifolium).
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields, woodlands
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
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- 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
- 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
- 30–70 mm
- Disk flower number
-
- 1-5
- 6-10
-
Flowers
- Bases of bract appendages
- NA
- Bract cycle number
-
- there are three or more cycles of bracts
- there are two main cycles of bracts
- Bract outer side hairs
- the bracts are hairy on their outer surfaces
- Bract shape
-
- the main bracts are elliptic (widest near the middle and tapered towards the base and tip)
- the main bracts are oblanceolate (widest near the tip, but otherwise narrow and tapering)
- Bract tip color
- the tips are a different color from the center of the bract
- Bract tip shape
-
- the tips of the bracts acute (have a sharp point)
- the tips of the bracts are obtuse (have a blunt point)
- Bract width
- 0.5–1.5
- Disk flower color
- white
- Disk flower lobe number
- 5
- Disk flower number
-
- 1-5
- 6-10
- Disk flower reproductive parts
- the disk flower has both pollen- and seed-producing parts
- Flower head platform
- the base has no bristles or papery scales
- Flower head platform surface
- NA
- Flower head position
- each of the flower heads is separate on its own peduncle (stalk), not clustered in groups
- Flower type in flower heads
- the flower head has disk flowers only, and lacks the strap-shaped flowers
- Height of flower head base
- 4.5–6.5 mm
- Inflorescence branching (Solidago)
- NA
- Inflorescence shape
- the inflorescence is flat-topped in profile
- Number of bracts at flower head base
- 8–10
- Ovary attachment
- the ovary is attached at or near the base
- Ovary lines or ribs
- there are four to six lines or ribs visible on the ovary
- Ray flower color
- NA
- Ray flower reproductive parts
- NA
- Ray flowers
- 0
- Ray length
- 0 mm
- Scale tip
- NA
- Smaller bracts at base of bracts
- there is no smaller, outer cycle of bracts
- Width of flower head base
- 2–3 mm
-
Fruits or seeds
- Number of pappus parts
- 11 or more
- Ovary length in developed fruit
- 2–3 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
- 3.5–4 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 glandular (translucent) dots or scales
- 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
- 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 fuzzy or hairy
- Hairs on upper side of leaf blade
- the upper side of the leaf is fuzzy or hairy
- Leaf arrangement
-
- alternate: there is one leaf per node along the stem
- opposite: there are two leaves per node along the stem
- Leaf blade base
-
- the leaf has a distinct petiole
- the leaf has no 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)
- Leaf blade bloom
- the underside of the leaf has no noticeable bloom
- Leaf blade edges
- the edge of the leaf blade has teeth
- Leaf blade hairs
- the leaf blade has hairs with glands at their tips
- Leaf blade length
- 30–70 mm
- Leaf blade shape
-
- 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 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
- 30–60 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
- the leaves have no leaf stalks, but attach directly to the stem
- Leaf stalk length
- 0–3 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
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
- woodlands
-
Scent
- Plant odor
- the plant does not have much of an odor
-
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
- there is no powdery or waxy film on the stem
- Stem internode hair direction
- the hairs point mostly upwards to outwards
- Stem internode hair type
- at least some of the hairs on the stem have glands
- Stem internode hairs
- the stem has hairs between the nodes
- Stem wings
- the stem does not have wings on it
Wetland status
Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- absent
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Maine
- extremely rare (S-rank: S1), endangered (code: E)
- New Hampshire
- extremely rare (S-rank: S1), endangered (code: E)
From Flora Novae Angliae dichotomous key
7. Eupatorium pubescens Muhl. ex Willd. N
hairy thoroughwort. Eupatorium rotundifolium L. var. ovatum (Bigelow) Torr. • CT, MA, ME, NH, RI. Dry-mesic, often sandy, woodlands, fields, and clearings. This species is thought to have been derived from hybridization between Eupatorium rotundifolium and E. sessilifolium.
Native to North America?
Yes
Sometimes confused with
- Eupatorium pilosum:
- leaf blades oblong or oblong-lanceolate to narrow-ovate, each margin with 3–12 coarse teeth, sometimes the blades more incised with lobe-like teeth near the base (vs. E. pubescens, with leaf blades oblong-ovate to suborbicular, each margin with 8–25 teeth).
- Eupatorium rotundifolium:
- leaf blades triangular-ovate to suborbicular, mostly 1–1.5 times as long as wide, rounded to obtuse at the apex, usually with crenate margins (vs. E. pubescens, with leaf blades oblong-ovate to ovate, mostly 1.5–2 times as long as wide, obtuse to acute at apex, usually with serrate margins).
Synonyms
- Eupatorium rotundifolium var. ovatum (Bigelow) Torr.