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• Eupatorium perfoliatum

Eupatorium perfoliatum — boneset thoroughwort

Facts

Native Americans used boneset thoroughwort for a large variety of medicinal purposes, and European settlers considered it something of a cure-all in the 18th and 19th centuries when they learned of it. An infusion of Eupatorium perfoliatum will relieve cold symptoms as well as having a laxative effect.

Habitat

Anthropogenic (man-made or disturbed habitats), marshes, shores of rivers or lakes, swamps, wetland margins (edges of wetlands)

Characteristics

• Flowers

  Bases of bract appendages

  NA

  Bract cycle number

  • there are three or more cycles of bracts
  • there are two main cycles of bracts
  • there is one main cycle of bracts

  Bract outer side hairs

  the bracts are hairy on their outer surfaces

  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 acuminate (tapered to a narrow point)

  Bract width

  0.6–1

  Disk flower color

  white

  Disk flower lobe number

  5

  Disk flower number

  • 11-20
  • 21-50
  • 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 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

  4–6 mm

  Inflorescence branching (Solidago)

  NA

  Inflorescence shape

  the inflorescence is flat-topped in profile

  Number of bracts at flower head base

  7–10

  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

• Fruits or seeds

  Number of pappus parts

  11 or more

  Ovary length in developed fruit

  1.5–2 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

  3–3.5 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 caudex (the root mass is firm and hardened at the top)

• 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 not hairy, or has very few hairs

  Leaf arrangement

  • opposite: there are two leaves per node along the stem
  • whorled: there are three or more leaves per node along the stem

  Leaf blade base

  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 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

  50–150 mm

  Leaf blade shape

  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is oblong (rectangular but with rounded 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 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 no leaf stalks, but attach directly to the stem

  Leaf stalk length

  0 mm

  Leaf tip extension

  NA

  Leaf type

  leaves are simple (lobed or unlobed but not separated into leaflets)

  Leaflet number

  0

  Specific leaf type

  the leaves are simple (lobed or unlobed but not separated into leaflets

• Place

  Habitat

  wetlands

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • edges of wetlands
  • man-made or disturbed habitats
  • marshes
  • shores of rivers or lakes
  • swamps

• 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 hairs

  the stem has hairs between the nodes

  Stem wings

  the stem does not have wings on it

Wetland status

Usually occurs in wetlands, but occasionally in non-wetlands. (Wetland indicator code: FACW)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae