Carduus nutans L.

nodding plumeless-thistle

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

Nodding plumeless-thistle is among the most serious weeds in North America. It is unpalatable to livestock and may form dense stands in pastures. It prefers disturbed sites in a variety of habitats. A single terminal head produces as many as 1200 seeds. Efforts to control infestations with a European seed head weevil (Rhinocyllus conicus) may be successful, but unfortunately the weevil also attacks native thistles (Cirsium species).

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • 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
  • basal: the leaves are growing only at the base of the plant
Leaf blade edges
the edge of the leaf blade has lobes, or it has both teeth and lobes
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
there are spines on the plant
Leaf blade length
100–400 mm
Flower head width
20–40 mm
Disk flower number
more than 50
Show All Characteristics
  • Flowers
    Bases of bract appendages
    NA
    Bract color
    the bracts are colored, or at least tinged with, pink, red or purple
    Bract cycle number
    there are three or more cycles of bracts
    Bract outer side hair type
    • the bracts are hairy on their outer surfaces, with curled, tangled, matted, or woolly hairs
    • the bracts are not hairy on their outer surface
    Bract outer side hairs
    • the bracts are hairy on their outer surfaces
    • the bracts are not 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 ovate (egg-shaped)
    Bract spines
    there is just one simple spine at the tip of the bract
    Bract tip extension appearance
    the projections from the bract tips are simple, but may be a different color than the bract
    Bract tip extension edge
    there are projections from the bract tips
    Bract tip orientation
    • the bracts are pressed against the plant, or spreading out at the tips
    • the tips of the bracts curve outwards and downwards from the plant
    Bract tip shape
    the tips of the bracts acute (have a sharp point)
    Bract width
    2–4
    Bracts
    there are at least two distinct forms of bracts in different cycles
    Disk flower color
    blue to purple
    Disk flower number
    more than 50
    Disk flower reproductive parts
    the disk flower has both pollen- and seed-producing parts
    Disk flower shape
    the disk flower is abruptly widened at some point below the lobes
    Disk width
    20–40 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, 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 fine, short hairs on it
    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 profile
    • the disk is conical across the top
    • the disk is flat or nearly flat across the top
    Flower head shape
    • the flower head is shaped like a cone with the point up
    • the sides of the flower head are roughly parallel, like a cylinder
    Flower head width
    20–40 mm
    Flower type in flower heads
    the flower head has disk flowers only, and lacks the strap-shaped flowers
    Height of flower head base
    20–60 mm
    Inflorescence branching (Solidago)
    NA
    Inflorescence shape
    • NA
    • the inflorescence is flat-topped in profile
    Inflorescence stem
    hairs are present on the stem of the inflorescence
    Ovary attachment
    the ovary is attached at the side near the base, rather than at the base
    Ovary cross-section
    the ovary is compressed (flattened)
    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 no 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 roughly egg-shaped, but widest above the middle
    Ovary surface
    the ovary surface has no points, bumps or wrinkles, though it may have lines, ribs or wings
    Peduncle length
    2–30 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 no smaller, outer cycle of bracts
    Style branch number
    the style has two branches
    Width of flower head base
    20–60 mm
  • Fruits or seeds
    Ovary length in developed fruit
    4–5 mm
    Seed hair tuft bases
    the pappus hairs are attached to one another near the base
    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
    13–25 mm
    Seed hairs uniform
    all the pappus hairs are approximately the same length
    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 biennial, it appears as either first year (non-reproductive) plants or second year plants with flowers or fruit
    Spines on plant
    there are spines on the plant
  • 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
    Leaf arrangement
    • alternate: there is one leaf per node along the stem
    • 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 blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
    Leaf blade edges
    the edge of the leaf blade has lobes, or it has both teeth and lobes
    Leaf blade hairs
    the leaf blade has simple hairs with no glands, and not tangled or wooly
    Leaf blade length
    100–400 mm
    Leaf blade shape
    • the leaf blade is elliptic (widest near the middle and tapering at both ends)
    • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
    Leaf blade surface colors
    there is no noticeable color variation on the upper surface of the leaf
    Leaf blade width
    50–120 mm
    Leaf disposition
    • the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
    • the lower leaves are larger, toothier, and/or on longer stalks than the upper leaves
    Leaf spines
    there are spines along the leaf edges
    Leaf stalk
    • the leaves have leaf stalks
    • the leaves have no leaf stalks, but attach directly to the stem
    Leaf tip extension
    NA
    Leaf type
    leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
    Specific leaf type
    • the leaf has a row of two or more lobes on each side of the central axis
    • the leaf has a row of two or more lobes on each side of the central axis, and each lobe itself has rows of lobes on each side of the lobe's central axis
  • Place
    Habitat
    terrestrial
    New England state
    • Connecticut
    • Massachusetts
    • New Hampshire
    • Rhode Island
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • Stem, shoot, branch
    Leaves on stem
    there is at least one full leaf above the base of the flowering stem
    Stem internode hair direction
    • NA
    • 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
    • the stem has no hairs between the nodes
    Stem internode hairs
    • the stem has hairs between the nodes
    • the stem has no hairs between the nodes
    Stem wings
    the stem has wings on it that run down the stem from the leaf nodes

Wetland Status

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

New England Distribution and Conservation Status

Distribution

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

Conservation Status

Exact status definitions can vary from state to state. For details, please check with your state.

Massachusetts
unranked (S-rank: SNR)

Native to North America?

No

Synonyms

  • Carduus nutans L. ssp. leiophyllus (Petrovic) Stojanov & Stef.
  • Carduus nutans L. var. leiophyllus (Petrovic) Arènes

Family

Asteraceae

Genus

Carduus

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Information from Dichotomous Key of Flora Novae Angliae

3.  Carduus nutans L. E

nodding plumeless-thistle. Carduus nutans L. ssp. leiophyllus (Petrovic) Stojanov & Stef.; 
 C. nutans L. var. leiophyllus (Petrovic) Arènes • CT, MA, NH, RI. Roadsides, fields, pastures.