Helianthus occidentalis — naked-stemmed 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 fine hairs along the bract margins

  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 shape

  • the main bracts are elliptic (widest near the middle and tapered towards the base and tip)
  • the main bracts are ovate (egg-shaped)

  Bract spines

  the bracts have no spines

  Bract tip shape

  • the tips of the bracts acute (have a sharp point)
  • 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

  yellow

  Disk flower number

  more than 50

  Disk flower reproductive parts

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

  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 rounded across the top

  Flower head shape

  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

  8–12 mm

  Inflorescence branching (Solidago)

  NA

  Ovary cross-section

  the ovary is compressed (flattened)

  Ovary hairs

  • the ovary has hairs on it
  • the ovary has no hairs on it

  Ray flower color

  yellow

  Ray flower reproductive parts

  there are neither carpels nor stamens in the ray flowers

  Ray flowers

  • 11-15
  • 6-10

  Ray length

  18–22 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

  9–14 mm

• Fruits or seeds

  Number of pappus parts

  2

  Ovary length in developed fruit

  3–5 mm

  Seed hair tuft bases

  NA

  Seed hair tuft color

  NA

  Seed hair tuft details

  NA

  Seed hair tuft tips

  NA

  Seed hairs uniform

  NA

  Seed tuft scale number

  2–6

  Seed tuft type

  • the pappus is made of flat scales that are not split or frayed at the tips
  • the pappus is made of stiff, tapering bristles

  Tuft or plume on fruit

  there is no plume, or the plume is made up of scales, awns, a crown, or a rim

• Growth form

  Growth form

  the plant has one or more free-standing stems

  Plant lifespan

  the plant is perennial, it shows evidence of previous year's leaves, stems or stem bases

  Spines on plant

  the plant has no spines

  Underground organs

  the plant has a rhizome (a horizontal underground stem with roots growing from it)

• 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
  • opposite: there are two leaves per node along the stem
  • the leaves are growing only at the base of the plant (basal)

  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 no teeth or lobes

  Leaf blade length

  50–200 mm

  Leaf blade shape

  • the leaf blade is elliptic (widest near the middle and tapering at both ends)
  • the leaf blade is lanceolate (lance-shaped; widest below the middle and tapering at both ends)
  • the leaf blade is oblong (rectangular but with rounded ends)
  • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)

  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

  30–100 mm

  Leaf disposition

  the lower leaves are larger, toothier, and/or on longer stalks than the upper leaves

  Leaf spines

  there are no spines on the leaf edges

  Leaf stalk

  the leaves have leaf stalks

  Leaf type

  leaves are simple (lobed or unlobed but not separated into leaflets)

  Specific leaf type

  the leaves are simple (lobed or unlobed but not separated into leaflets

• Place

  Habitat

  terrestrial

  New England state

  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 are pressed flat against the plant, pointing either towards the plant's tip or towards it's base
  • the hairs point mostly upwards to outwards

  Stem internode hairs

  the stem has hairs between the nodes

Wetland status

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

In New England

From Flora Novae Angliae dichotomous key