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- Dichotomous Key
- Asteraceae
- Asteraceae Group 3
- Xanthium
- Xanthium spinosum
Xanthium spinosum — spiny cocklebur
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Facts
The origins of spiny cocklebur is not resolved. It may be introduced everywhere north of South America, or it may be native in much of its northern hemisphere distribution. Because of its burs, it probably reached New England mainly as a waste product of the wool-carding industry in the nineteenth century.
Habitat
Anthropogenic (man-made or disturbed habitats)
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
- Maine
- 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
- Leaf blade edges
-
- the edge of the leaf blade has no teeth or lobes
- 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
- there is no plume, or the plume is made up of scales, awns, a crown, or a rim
- Spines on plant
- there are spines on the plant
- Leaf blade length
- 40–120 mm
- Disk flower number
- 21-50
-
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 hair type
- the bracts are hairy, with simple hairs on their outer surface
- Bract outer side hairs
- the bracts are hairy on their outer surfaces
- Bract separation
-
- at least some flower heads have bracts connected to one another at or near their bases
- the bracts appear completely unconnected to one another on all flower heads
- Disk flower color
-
- NA
- white
- Disk flower lobe number
- 5
- Disk flower number
- 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
- Flower head number
- 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 papery scales on it
- Flower head platform surface
- the scales are slightly hairy, at least near the top
- 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
-
- NA
- the disk is conical across the top
- Flower head shape
- NA
- Flower type in flower heads
- the flower head has disk flowers only, and lacks the strap-shaped flowers
- Height of flower head base
- 8–40 mm
- Inflorescence branching (Solidago)
- NA
- Inflorescence shape
- the inflorescence is not flat-topped but appears rounded, with some flower heads distinctly higher than others
- Ovary beak
- there is a beak on the ovary
- 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 profile
- in profile, the ovary is roughly elliptical (widest in the middle, tapering to both ends)
- Ray flower color
- NA
- Ray flower reproductive parts
- NA
- Ray flowers
- NA
- Ray length
- 0 mm
- Reproductive system
- the flowers on the plant may have either carpels or stamens, but always in separate flowers
- Style branch number
- there are no obvious branches on the style
- Width of flower head base
- 6–8 mm
-
Fruits or seeds
- Dispersal unit
- the entire flower head falls off or disperses as a unit
- Number of pappus parts
- NA
- Ovary length in developed fruit
- 10–15 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
- there is no plume, or the plume is made up of scales, awns, a crown, or a rim
-
Glands or sap
- Leaf blade glands
-
- the leaf blades have glandular (translucent) dots or scales
- the leaf blades have no 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 annual, it lacks evidence of previous years' growth
- Spines on plant
- there are spines on the plant
- Underground organs
- there is a thickened taproot on the plant
-
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 fuzzy or hairy
- Leaf arrangement
- alternate: there is one leaf per node along the stem
- Leaf blade base
- the leaf has a distinct 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 bloom
- the underside of the leaf has no noticeable bloom
- Leaf blade edges
-
- the edge of the leaf blade has no teeth or lobes
- the edge of the leaf blade has teeth
- Leaf blade hairs
- the leaf blade has simple hairs with no glands, and not tangled or wooly
- Leaf blade length
- 40–120 mm
- Leaf blade shape
- the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
- 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
- 10–50 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
- 1–25 mm
- Leaf tip extension
- NA
- Leaf type
- leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
- Leaflet number
- 0
- Specific leaf type
- the leaves are simple (i.e., lobed or unlobed but not separated into leaflets
-
Place
- Habitat
- terrestrial
- New England state
-
- Connecticut
- Maine
- Massachusetts
- New Hampshire
- Rhode Island
- Specific habitat
- man-made or disturbed habitats
-
Stem, shoot, branch
- Leaves on stem
- there is at least one full leaf above the base of the flowering stem
- Stem internode hair direction
- the hairs are pressed flat against the plant, pointing either towards the plant's tip or towards it's base
- Stem internode hair type
-
- the hairs on the stem are plain, without glands or branches, and not tangled
- 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
Wetland status
Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)
In New England
Distribution
- Connecticut
- present
- Maine
- present
- Massachusetts
- present
- New Hampshire
- present
- Rhode Island
- present
- Vermont
- absent
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
1. Xanthium spinosum L. E
spiny cocklebur. Acanthoxanthium spinosum (L.) Fourr.; Xanthium spinosum L. var. inerme Bel. • CT, MA, ME, NH, RI. Waste areas, disturbed ground, often in the vicinity of old mills.
Native to North America?
No
Sometimes confused with
- Xanthium strumarium:
- leaf blades ovate to reniform, truncate to cordate at the base, abaxially +/- green, hirtellous, and plants without axillary spines (vs. X. spinosum, with leaf blades lanceolate, tapering to the base, abaxially gray to white and densely strigose, and plants with 3-forked, axillary spines).
Synonyms
- Acanthoxanthium spinosum (L.) Fourr.
- Xanthium spinosum L. var. inerme Bel.