Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

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

Cosmos sulphureus — sulphur cosmos

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Sulphur cosmos is native to Mexico and introduced around the world. It is a popular garden annual, with several cultivars. It is recorded from Connecticut and Massachusetts.

Habitat

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

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Massachusetts
Leaf type
leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
Leaf arrangement
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
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
yellow
Tuft or plume on fruit
  • NA
  • there is no plume, or the plume is made up of scales, awns, a crown, or a rim
Spines on plant
the plant has no spines
Leaf blade length
50–250 mm
Disk flower number
  • 11-20
  • 21-50
  • 6-10
  • more than 50
Show all characteristics
  • Flowers

    Bases of bract appendages
    NA
    Bract cycle number
    there are two main cycles of bracts
    Bract outer side hair type
    • the bracts are hairy, with simple hairs on their outer surface
    • 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 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
    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 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 texture
    • the bracts appear thin, flexible and nearly translucent
    • the bracts have a similar texture to a leaf
    Bract tip color
    • the tips are a different color from the center of the bract
    • the tips are the same color as the center of the bract
    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)
    • the tips of the bracts are rounded
    Bracts
    there are at least two distinct forms of bracts in different cycles
    Disk flower color
    • orange
    • yellow
    Disk flower lobe number
    5
    Disk flower number
    • 11-20
    • 21-50
    • 6-10
    • more than 50
    Disk flower reproductive parts
    the disk flower has both pollen- and 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, 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
    Flower head shape
    • the flower head is hemispherical (like the bottom half of a sphere)
    • the sides of the flower head are roughly parallel, like a cylinder
    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
    Inflorescence branching (Solidago)
    NA
    Inflorescence shape
    • NA
    • the inflorescence is flat-topped in profile
    Ovary beak
    there is a beak on the ovary
    Ovary cross-section
    • the ovary is compressed (flattened)
    • the ovary is roughly square or with four corners
    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 profile
    in profile, the ovary is another shape
    Peduncle hair type
    the hairs on the peduncles are simple (not branched), don’t have glands, and are not woolly
    Peduncle hairs
    • the peduncles are hairy
    • the peduncles have no hairs
    Peduncle length
    100–200 mm
    Ray flower color
    yellow
    Ray flower reproductive parts
    • the ray flowers have carpels or stamens, but not both
    • there are neither carpels nor stamens in the ray flowers
    Ray flowers
    • 0
    • 6-10
    Ray length
    18–30 mm
    Reproductive system
    all the flowers on the plant contain both carpels and stamens
    Style branch number
    the style has two branches
    Style branches
    the style branch is wider at the tip and has a flattened end, or the style branches are wider at the tips and have flattened ends
    Width of flower head base
    6–10 mm
  • Fruits or seeds

    Number of pappus parts
    • 0
    • 2
    Ovary length in developed fruit
    15–30 mm
    Seed hair tuft bases
    NA
    Seed hair tuft color
    NA
    Seed hair tuft details
    NA
    Seed hair tuft length
    0–7 mm
    Seed hair tuft tips
    NA
    Seed hairs uniform
    NA
    Seed tuft scale number
    0–2
    Seed tuft type
    the pappus is made of stiff, tapering bristles
    Top of disk flower ovary
    NA
    Tuft or plume on fruit
    • NA
    • 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 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
    the plant has no spines
  • Leaves

    Final leaf segment width (compound lvs only)
    2–5 mm
    Hairs on underside of leaf blade
    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 not hairy, or has very few hairs
    Leaf arrangement
    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 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
    NA
    Leaf blade length
    50–250 mm
    Leaf blade shape
    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 tip
    the tip of the leaf blade is rounded, with no point
    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
    10–70 mm
    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
    • the leaf has lobes that themselves have lobes, and these secondary lobes also have lobes; there may be more than three levels of lobes
  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Massachusetts
    Specific habitat
    • man-made or disturbed habitats
    • meadows or fields
  • 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
    • 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
    Stem wings
    the stem does not have wings on it

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
absent
Rhode Island
absent
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

3.  Cosmos sulphureus Cav. E

sulphur cosmos. CT, MA. Fields, roadsides, waste areas.

Native to North America?

No

Family

Asteraceae

Genus

Cosmos