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- Petasites hybridus
Petasites hybridus — butterbur sweet-coltsfoot
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Facts
Butterbur sweet-coltsfoot is native to Europe and an occasional visitor to North America. This distinctive wetland plant has unmistakable flowers as well as giant rhubarb-like leaves up to three feet across. Clinical trials have shown that extracts of butterbur root are effective in reducing frequency and severity of migraine.
Habitat
Anthropogenic (man-made or disturbed habitats), meadows and fields, shores of rivers or lakes
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
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Leaf type
- leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaf arrangement
- basal: the leaves are growing only at the base of the plant
- 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
- 100–300 mm
- Disk flower number
-
- 11-20
- more than 50
-
Flowers
- Bract color
- the bracts are colored, or at least tinged with, pink, red or purple
- Bract cycle number
-
- there are two main cycles of bracts
- there is one main cycle of bracts
- Bract keels
- there is one distinct keel on the bracts
- Bract margins
- there are few or no 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 shape
-
- the main bracts are oblanceolate (widest near the tip, but otherwise narrow and tapering)
- the main bracts are oblong (roughly rectangular but rounded at the ends)
- Bract spines
- the bracts have no spines
- 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
- 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
- 5–16
- Bracts
- the bracts in separate cycles are similar or gradually changing from the outer to inner cycles
- Disk flower color
- blue to purple
- Disk flower lobe number
- 5
- Disk flower number
-
- 11-20
- more than 50
- Disk flower reproductive parts
- the disk flower has either only pollen- or only 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
- each flowering stem has only one to three 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 flat or nearly flat across the top
- the disk is rounded across the top
- Flower head shape
-
- NA
- the flower head is shaped like a cone with the point up
- Flower type in flower heads
- the flower head has disk flowers only, and lacks the strap-shaped flowers
- Height of flower head base
- 2.5–8.5 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 cross-section
- the ovary has five or more corners in cross-section
- Ovary hair type
- the ovary has no hairs on it
- Ovary hairs
- the ovary has no hairs on it
- Ovary lines or ribs
-
- there are four to six lines or ribs visible on the ovary
- there are seven to nine ribs visible on the ovary
- there are ten or more ribs visible on the ovary
- Ovary profile
- in profile, the ovary is very narrow
- Peduncle hair type
- the hairs on the peduncles appear tangled or woolly
- Peduncle hairs
- the peduncles are hairy
- Ray flower color
- NA
- Ray flower reproductive parts
- NA
- Ray flowers
- 0
- Ray length
- 0 mm
- Reproductive system
- all the flowers on some plants have carpels, while all the flowers on other plants have 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
-
Fruits or seeds
- Number of pappus parts
- 1
- Ovary length in developed fruit
- Up to 3 mm
- Seed hair tuft details
- the pappus hairs are smooth and plain
- Seed hair tuft tips
- the pappus hairs are slender
- 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
- 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
- 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
- basal: the leaves are growing only at the base of the plant
- Leaf blade base
-
- the leaf has a distinct petiole
- the leaf has no petiole
- Leaf blade base shape
- the base of the leaf is cordate (heart-shaped) or sagittate (arrow-shaped)
- 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 tangled or woolly-looking hairs
- Leaf blade length
- 100–300 mm
- Leaf blade shape
-
- NA
- the leaf blade is cordate (heart-shaped with backward-facing rounded lobes), or sagittate (arrow-shaped with backward-facing pointed lobes)
- the leaf blade is orbicular (roughly circular, as wide as long)
- 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 rounded, with no point
- Leaf blade veins
- NA
- Leaf blade width
- 100–300 mm
- Leaf disposition
- the lower leaves are larger, toothier, and/or on longer stalks than the upper leaves
- 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 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 leaf has lobes that radiate from the base, somewhat like a hand
-
Place
- Habitat
-
- terrestrial
- wetlands
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Vermont
- Specific habitat
-
- man-made or disturbed habitats
- meadows or fields
- shores of rivers or lakes
-
Stem, shoot, branch
- Flowering stem cross-section
- the flowering stem is circular, or with lots of small angles
- Leaves on stem
- the flowering stem has no leaves above the base
- Stem internode hair direction
- the hairs point mostly upwards to outwards
- Stem internode hair type
- at least some of the hairs on the stem are tangled, matted or woolly
- Stem internode hairs
- the stem has hairs between the nodes
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
- absent
- Vermont
- present
Conservation status
Exact status definitions can vary from state to state. For details, please check with your state.
- Massachusetts
- not applicable (S-rank: SNA)
From Flora Novae Angliae dichotomous key
2. Petasites hybridus (L.) P.G. Gaertn., B. Mey., & Scherb. E
butterbur sweet-coltsfoot. Petasites officinalis Moench; P. vulgaris Hill • CT, MA, ME, NH, VT. Roadsides, fields, stream banks.
Native to North America?
No
Sometimes confused with
- Petasites japonicus:
- disk corollas cream-white, bracts of scape usually green, the one subtending the lowermost branch of the capitulescence 17–40 mm wide, and leaf blades with mostly 5 pairs of lateral veins emerging along the inner margins of the basal sinus (vs. P. hybridus, with the disk corollas largely purple, bracts of scape usually purple or purple-tinged, the one subtending the lowermost branch of the capitulescence 5–16 mm wide, and leaf blades with 2–5 pairs of lateral veins emerging along the inner margins of the basal sinus).
Synonyms
- Petasites officinalis Moench
- Petasites vulgaris Hill