Cosmos bipinnatus — garden cosmos

Characteristics

• Flowers

  Bases of bract appendages

  NA

  Bract cycle number

  there are two main cycles of bracts

  Bract margins

  there are few or no fine hairs along the bract margins

  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 texture

  the bracts have a similar texture to a leaf

  Bract tip shape

  • 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

  yellow

  Disk flower lobe number

  5

  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

  Disk width

  10–15 mm

  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 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)

  Flower head width

  10–15 mm

  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

  7–15 mm

  Inflorescence branching (Solidago)

  NA

  Number of bracts at flower head base

  8

  Ovary beak

  there is a beak on the ovary

  Ovary cross-section

  the ovary is roughly square or with four corners

  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 very narrow

  Ovary surface

  the ovary surface is textured with tiny points, bumps or wrinkles

  Peduncle length

  100–200 mm

  Ray flower color

  • blue to purple
  • pink to red
  • white

  Ray flower reproductive parts

  there are neither carpels nor stamens in the ray flowers

  Ray flowers

  6-10

  Ray length

  15–40 mm

  Reproductive system

  all the flowers on the plant contain both carpels and stamens

  Smaller bracts at base of bracts

  there is a cycle of much smaller bracts outside the cycle of larger and longer bracts

  Style branches

  the style branch is narrow at the tip, or the style branches are narrow at the tips

  Width of flower head base

  7–15 mm

• Fruits or seeds

  Number of pappus parts

  • 0
  • 2
  • 3

  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

  0–3 mm

  Seed hair tuft tips

  NA

  Seed hairs uniform

  NA

  Seed tuft scale number

  0

  Seed tuft type

  • the pappus is made of stiff, tapering bristles
  • 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 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

  Underground organs

  there is a thickened taproot on the plant

• Leaves

  Final leaf segment length (compound lvs only)

  0.5–6 mm

  Final leaf segment width (compound lvs only)

  Up to 1.5 mm

  Hairs on underside of leaf blade

  the underside 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
  • the leaf has no petiole

  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

  Leaf blade length

  60–110 mm

  Leaf blade shape

  • the leaf blade is filiform (extremely narrow, thread-like)
  • 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)

  Leaf blade veins

  the leaf blade has one main vein running from the base towards the tip

  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
  • the leaves have no leaf stalks, but attach directly to the stem

  Leaf stalk length

  0–1 mm

  Leaf tip extension

  NA

  Leaf type

  leaves are compound (made up of two or more discrete leaflets)

  Specific leaf type

  the leaf is compound, there are two or more discrete leaflets

  Teeth per side of leaf blade

  0

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island

  Specific habitat

  man-made or disturbed habitats

• Scent

  Plant odor

  the plant does not have much of an odor

• 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 bloom

  there is no powdery or waxy film on the stem

  Stem internode hair length

  At least 0 mm

  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

Occurs in wetlands or non-wetlands. (Wetland indicator code: FAC)

In New England

From Flora Novae Angliae dichotomous key