Helianthus petiolaris — prairie sunflower

Characteristics

• Flowers

  Bract cycle number

  • there are three or more cycles of bracts
  • there are two main cycles of bracts

  Bract margins

  • there are few or no fine hairs along the bract margins
  • there are fine hairs along the bract margins

  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 shape

  the main bracts are lanceolate (widest above the base, then taper narrowly towards the tip)

  Bract spines

  the bracts have no spines

  Bract tip orientation

  the bracts are pressed against the plant, or spreading out at the tips

  Bract tip shape

  the tips of the bracts are acuminate (tapered to a narrow point)

  Bracts

  the bracts in separate cycles are similar or gradually changing from the outer to inner cycles

  Disk flower color

  • blue to purple
  • pink to red

  Disk flower number

  more than 50

  Disk flower reproductive parts

  the disk flower has both pollen- and seed-producing parts

  Disk width

  10–25 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, 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 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

  the inflorescence is not flat-topped but appears rounded, with some flower heads distinctly higher than others

  Ovary beak

  there is no beak on the ovary

  Ovary cross-section

  the ovary is compressed (flattened)

  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

  Ray flower color

  yellow

  Ray flower reproductive parts

  there are neither carpels nor stamens in the ray flowers

  Ray flowers

  • 11-15
  • 16-25
  • 26-50
  • 6-10

  Ray length

  30–50 mm

  Reproductive system

  some of the flowers on the plant have only carpels or stamens, while others have both carpels and stamens

  Style branch number

  the style has two branches

  Width of flower head base

  10–24 mm

• Fruits or seeds

  Number of pappus parts

  2

  Ovary length in developed fruit

  3–4.5 mm

  Seed hair tuft bases

  NA

  Seed hair tuft color

  NA

  Seed hair tuft details

  NA

  Seed hair tuft length

  1–5 mm

  Seed hair tuft tips

  NA

  Seed hairs uniform

  NA

  Seed tuft scale number

  2–6

  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

• 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 are only slender roots on the plant

• Leaves

  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
  • the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)
  • the base of the leaf is cordate (heart-shaped) or sagittate (arrow-shaped)

  Leaf blade edges

  the edge of the leaf blade has no teeth or lobes

  Leaf blade length

  40–150 mm

  Leaf blade shape

  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
  • the leaf blade is triangular, with the stalk or attachment point on one of the sides

  Leaf blade tip

  the tip of the leaf blade is acute (sharply pointed)

  Leaf blade veins

  the leaf blade has three main veins running from the base towards the tip

  Leaf blade width

  15–90 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

  10–120 mm

  Leaf type

  leaves are simple (i.e., lobed or unlobed but not separated into leaflets)

  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
  • Vermont

  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 hairs

  the stem has hairs between the nodes

Wetland status

Not classified

In New England

From Flora Novae Angliae dichotomous key