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Native Plant Trust: Go Botany Discover thousands of New England plants

Polymnia canadensis — white-flowered leaf-cup

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Facts

White-flowered leaf-cup is rare in New England, with only a few populations present in Connecticut and Vermont. It is most frequently found on calcareous soils in dry to moist woodland slopes. The genus is named after the ancient Greek goddess Polymnia, daughter of Zeus and one of the nine Muses. She presided over lyric poetry and was believed to have invented the lyre.

Habitat

Cliffs, balds, or ledges, forests, woodlands

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Vermont
Leaf type
leaves are simple (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 lobes, or it has both teeth and lobes
  • the edge of the leaf blade has teeth
Flower type in flower heads
the flower head has tubular disk flowers in the center and ray flowers, these often strap-shaped, around the periphery
Ray flower color
  • white
  • yellow
Tuft or plume on fruit
NA
Spines on plant
the plant has no spines
Leaf blade length
40–400 mm
Disk flower number
  • 11-20
  • 21-50
Show all characteristics
  • Flowers

    Bract color
    the bracts are not colored or tinged with with pink, red or purple
    Bract cycle number
    there is one main cycle of bracts
    Bract outer side hair type
    the bracts are hairy on their outer surfaces, with hairs having glands (a swelling at the tip of the hair)
    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)
    • the main bracts are ovate (egg-shaped)
    Bract spines
    NA
    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 orientation
    the bracts are pressed against the plant, or spreading out at the tips
    Bracts
    the bracts in separate cycles are similar or gradually changing from the outer to inner cycles
    Disk flower color
    yellow
    Disk flower lobe number
    5
    Disk flower number
    • 11-20
    • 21-50
    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
    Disk width
    6–13 mm
    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, each flower has a single enlarged lobe or strap
    Flower head platform
    the base has papery scales on it
    Flower head position
    • each of the flower heads is separate on its own peduncle (stalk), not clustered in groups
    • 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
    the flower head is hemispherical (like the bottom half of a sphere)
    Flower type in flower heads
    the flower head has tubular disk flowers in the center and ray flowers, these often strap-shaped, around the periphery
    Height of flower head base
    6–11 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
    6–21
    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
    • the ovary has no hairs on it
    Ovary hairs
    • the ovary has hairs on it
    • the ovary has no hairs on it
    Ovary lines or ribs
    there are three lines or ribs visible on the ovary
    Ovary profile
    in profile, the ovary is another shape
    Peduncle hairs
    the peduncles are hairy
    Peduncle orientation
    the flower heads are arching outwards or downwards
    Ray flower color
    • white
    • yellow
    Ray flower reproductive parts
    the ray flowers have carpels or stamens, but not both
    Ray flowers
    • 1-5
    • 6-10
    Ray length
    Up to 15 mm
    Reproductive system
    all the flowers on the plant contain both carpels and stamens
    Scale tip
    the scales are obtuse (bluntly pointed) at the top
    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 one branch
    Style branches
    the style branch is narrow at the tip, or the style branches are narrow at the tips
    Width of flower head base
    4–15 mm
  • Fruits or seeds

    Number of pappus parts
    NA
    Ovary length in developed fruit
    3–4 mm
    Seed hair tuft bases
    NA
    Seed hair tuft color
    NA
    Seed hair tuft details
    NA
    Seed hair tuft length
    0 mm
    Seed hair tuft tips
    NA
    Seed hairs uniform
    NA
    Seed tuft scale number
    0
    Seed tuft type
    there is no pappus on the ovary
    Top of disk flower ovary
    NA
    Tuft or plume on fruit
    NA
  • Glands or sap

    Leaf blade glands
    the leaf blades have glandular (translucent) dots or scales
    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
    • the underside of the leaf is not hairy, or has very few hairs
    Hairs on upper side of leaf blade
    • the upper side of the leaf is fuzzy or hairy
    • the upper side of the leaf is not hairy, or has very few hairs
    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
    Leaf blade base shape
    the base of the leaf is cordate (heart-shaped) or sagittate (arrow-shaped)
    Leaf blade edges
    • the edge of the leaf blade has lobes, or it has both teeth and lobes
    • the edge of the leaf blade has teeth
    Leaf blade flatness
    the leaf is flat (planar) at the edges
    Leaf blade hairs
    • the leaf blade has hairs with glands at their tips
    • the leaf blade has simple hairs with no glands, and not tangled or wooly
    Leaf blade length
    40–400 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 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 acuminate (tapers to a long, thin point)
    • the tip of the leaf blade is acute (sharply pointed)
    Leaf blade veins
    the leaf blade has one main vein running from the base towards the tip
    Leaf blade width
    20–250 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
    30–120 mm
    Leaf type
    leaves are simple (lobed or unlobed but not separated into leaflets)
    Leaflet number
    0
    Specific leaf type
    the leaf has a row of two or more lobes on each side of the central axis
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Vermont
    Specific habitat
    • cliffs, balds, or ledges
    • forests
    • woodlands
  • 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 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

Wetland status

Not classified

In New England

Distribution

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

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)
Vermont
extremely rare (S-rank: S1), endangered (code: E)

From Flora Novae Angliae dichotomous key

1.  Polymnia canadensis L. NC

white-flowered leaf-cup. Polymnia canadensis L. var. radiata Gray; P. radiata (Gray) Small 
• CT, VT. Mesic to dry-mesic forests and woodlands on rocky slopes and ridges, also at cliff bases and among talus slopes, usually in regions of circumneutral to basic bedrock.

Native to North America?

Family

Asteraceae

Genus

Polymnia