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- Cosmos parviflorus
Cosmos parviflorus — southwestern cosmos
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Facts
Southwestern cosmos, as the name suggests, is not native to New England, but has been recorded from Massachusetts , Maine and Rhode Island. It is a tall, slender annual, with barbed seeds that cling to clothing and fur for dispersal.
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.
Found this plant? Take a photo and post a sighting.
Characteristics
- Habitat
- terrestrial
- New England state
-
- Maine
- Massachusetts
- Rhode Island
- 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
-
- pink to red
- white
- 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
- 25–65 mm
- Disk flower number
-
- 11-20
- 21-50
- 6-10
- more than 50
-
Flowers
- Bract color
- the bracts are not colored or tinged with pink, red or purple
- 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
- the bracts appear completely unconnected to one another on all flower heads
- Bract shape
- 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
- Bract tip extension appearance
- NA
- Bract tip extension edge
- there are no projections from the bract tips
- 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)
- Bracts
- there are at least two distinct forms of bracts in different cycles
- Disk flower color
- 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
- 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
- Height of flower head base
- 3–15 mm
- 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
- Ovary hairs
- the ovary has 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
- 100–300 mm
- Ray flower color
-
- pink to red
- white
- 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
- 1-5
- 6-10
- Ray length
- 5–9 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
- 3–15 mm
-
Fruits or seeds
- Number of pappus parts
-
- 2
- 3
- 4
- Ovary length in developed fruit
- 7–16 mm
- Seed hair tuft bases
- NA
- Seed hair tuft color
- NA
- Seed hair tuft details
- NA
- Seed hair tuft length
- 2–3 mm
- Seed hair tuft tips
- NA
- Seed hairs uniform
- NA
- Seed tuft scale number
- 2–4
- 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)
- Up to 1.4 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
- 25–65 mm
- Leaf blade shape
- the leaf blade is linear (very narrow with more or less parallel sides)
- 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 acute (sharply pointed)
- the tip of the leaf blade is obtuse (bluntly pointed)
- Leaf blade width
- Up to 1 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
- 5 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
-
- Maine
- Massachusetts
- Rhode Island
- 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
- 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
- absent
- Maine
- present
- Massachusetts
- present
- New Hampshire
- absent
- 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
2. Cosmos parviflorus (Jacq.) Pers. E
southwestern cosmos. MA, ME, RI. Roadsides, waste areas, wool waste.
Native to North America?
No
Sometimes confused with
- Cosmos bipinnatus:
- rays 15–40 mm long and margins of ultimate leaf segments entire (vs. C. parviflorus, with rays 5-15 mm long and margins of ultimate leaf segments spinulose-ciliate).