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• Vernonia fasciculata

Vernonia fasciculata — prairie ironweed

Facts

Prairie ironweed, as the name suggests, is native to the grasslands of the midwest. It is grown as an ornamental plant, for its dramatic height and purple flowers. Prairie ironweed has been collected in Massachusetts, but does not commonly escape from New England gardens.

Habitat

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

Characteristics

• Flowers

  Bases of bract appendages

  NA

  Bract color

  the bracts are colored, or at least tinged with, pink, red or purple

  Bract cycle number

  there are three or more 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 lanceolate (widest above the base, then taper narrowly towards the tip)
  • the main bracts are linear (long and very narrow)
  • the main bracts are oblong (roughly rectangular but rounded at the ends)
  • the main bracts are ovate (egg-shaped)

  Bract tip extension appearance

  NA

  Bract tip extension edge

  NA

  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

  Disk flower color

  • blue to purple
  • pink to red
  • white

  Disk flower number

  • 11-20
  • 21-50

  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

  Flower head outer flowers

  at the outer edge of the flower head, the flowers have no enlarged lobe or strap, and are of similar size as those in the center of the disk

  Flower head platform

  the base has no bristles or papery scales

  Flower head platform surface

  NA

  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
  • 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 disk flowers only, and lacks the strap-shaped flowers

  Height of flower head base

  5–8 mm

  Inflorescence branching (Solidago)

  NA

  Inflorescence shape

  the inflorescence is flat-topped in profile

  Inflorescence stem

  hairs are present on the stem of the inflorescence

  Number of bracts at flower head base

  25–35

  Ovary cross-section

  the ovary has five or more corners in cross-section

  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 lines or ribs

  • there are seven to nine ribs visible on the ovary
  • there are ten or more ribs visible on the ovary

  Ovary profile

  in profile, the ovary is oblong (roughly rectangular but rounded at the ends)

  Peduncle length

  1–12 mm

  Ray flower color

  NA

  Ray flower reproductive parts

  NA

  Ray flowers

  NA

  Ray length

  0 mm

  Reproductive system

  all the flowers on the plant contain both carpels and stamens

  Scale tip

  NA

  Smaller bracts at base of bracts

  there is no smaller, outer cycle of bracts

  Style branch number

  the style has two branches

  Style branches

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

  Width of flower head base

  4–6 mm

• Fruits or seeds

  Number of pappus parts

  11 or more

  Ovary length in developed fruit

  3.5–4 mm

  Seed hair tuft color

  the pappus hairs are another color

  Seed hair tuft length

  0.5–7 mm

  Seed hair tuft tips

  the pappus hairs are slender

  Seed hairs uniform

  there are two distinct lengths of pappus hairs

  Seed tuft scale number

  20–30

  Seed tuft type

  • the pappus is made of flat scales that are not split or frayed at the tips
  • the pappus is made of very fine hairs or bristles

  Top of disk flower ovary

  NA

  Tuft or plume on fruit

  • at least a part of the plume is made up of fine bristles
  • 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

  Ovary glands

  there are glands on the ovary surface

  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 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)
  • there are only slender roots on the plant

• Leaves

  Hairs on underside of leaf blade

  • the underside of the leaf is fuzzy or hairy
  • 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 fuzzy or hairy
  • the upper side of the leaf is not hairy, or has very few hairs

  Leaf arrangement

  alternate: there is one leaf per node along the stem

  Leaf blade base

  the leaf has no 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 bloom

  the underside of the leaf has no noticeable bloom

  Leaf blade edges

  the edge of the leaf blade has teeth

  Leaf blade hairs

  the leaf blade has simple hairs with no glands, and not tangled or wooly

  Leaf blade length

  50–200 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 acuminate (tapers to a long, thin point)
  • 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 blade width

  5–40 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 no leaf stalks, but attach directly to the stem

  Leaf tip extension

  NA

  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

  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 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

Wetland status

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

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae