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- Carduus nutans
Carduus nutans — nodding plumeless-thistle
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Facts
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
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
- Massachusetts
- New Hampshire
- Rhode Island
- 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
- the leaves are growing only at the base of the plant (basal)
- 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
-
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
- the leaves are growing only at the base of the plant (basal)
- 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 (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)
In New England
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)
From Flora Novae Angliae dichotomous key
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.
Native to North America?
No
Synonyms
- Carduus nutans L. ssp. leiophyllus (Petrovic) Stojanov & Stef.
- Carduus nutans L. var. leiophyllus (Petrovic) Arènes