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• Asteraceae Group 4
• Oligoneuron
• Oligoneuron album

Oligoneuron album — white flat-topped-goldenrod

Facts

White flat-topped-goldenrod has travelled from genus to genus several times, first being considered an aster based on superficial resemblance, then moved to the goldenrods (Solidago) based on its ability to hybridize with species from that genus. It has now been placed in the genus Oligoneuron with a number of other species formerly included in Solidago. White flat-topped-goldenrod is rare in New England, being found in deciduous woodlands, cliffs and river shores, often on high-pH substrate. This species has white ray flowers.

Habitat

Cliffs, balds, or ledges, shores of rivers or lakes, woodlands

Characteristics

• Flowers

  Bract color

  the bracts are not colored or tinged with pink, red or purple

  Bract cycle number

  there are three or more cycles of bracts

  Bract inner side hairs

  the bracts are not hairy on their inner surfaces

  Bract keels

  there is one distinct keel on the bracts

  Bract outer side hair type

  the bracts are not hairy on their outer surface

  Bract outer side hairs

  the bracts are not hairy on their outer surfaces

  Bract shape

  the main bracts are linear (long and very narrow)

  Bract spines

  the bracts have no spines

  Bract texture

  the bracts appear leathery or hardened

  Bract tip color

  the tips are the same color as 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)
  • the tips of the bracts are obtuse (have a blunt point)

  Bracts

  there are at least two distinct forms of bracts in different cycles

  Disk flower color

  white

  Disk flower lobe number

  5

  Disk flower number

  21-50

  Disk flower reproductive parts

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

  Disk flower shape

  the disk flower is abruptly widened at some point below the lobes

  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 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

  Flower head shape

  the sides of the flower head are roughly parallel, like a cylinder

  Flower head width

  40–90 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

  5–6 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

  Ovary beak

  there is no beak on the ovary

  Ovary cross-section

  the ovary is compressed (flattened)

  Ovary hair type

  the ovary has no hairs on it

  Ovary hairs

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

  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

  Peduncle length

  29–36.5 mm

  Peduncle orientation

  the flower heads are held upright, or slightly angled outwards

  Ray flower color

  white

  Ray flower reproductive parts

  the ray flowers have carpels or stamens, but not both

  Ray flowers

  • 11-15
  • 16-25

  Ray length

  5–9 mm

  Reproductive system

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

  Scale tip

  NA

  Smaller bracts at base of bracts

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

  Style branch number

  the style has two branches

• Fruits or seeds

  Number of pappus parts

  11 or more

  Ovary length in developed fruit

  1–1.5 mm

  Seed hair tuft details

  the pappus hairs have smaller hairs along their sides

  Seed hair tuft length

  3.4–4 mm

  Seed hair tuft tips

  at least some of the pappus hairs are broader at their tips than their bases

  Seed hairs uniform

  all the pappus hairs are approximately the same length

  Seed tuft scale number

  0

  Seed tuft type

  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

• Glands or sap

  Leaf blade glands

  the leaf blades have 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 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

  Final leaf segment length (compound lvs only)

  0 mm

  Final leaf segment width (compound lvs only)

  0 mm

  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 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 a distinct petiole
  • 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 no teeth or lobes

  Leaf blade hairs

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

  Leaf blade length

  20–100 mm

  Leaf blade shape

  • the leaf blade is linear (very narrow with more or less parallel sides)
  • the leaf blade is oblanceolate (lance-shaped, but with the widest point above the middle of the leaf blade)

  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 blade width

  2–10 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
  • the leaves have no leaf stalks, but attach directly to the stem

  Leaf type

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

  Leaflet number

  0

  Specific leaf type

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

  Teeth per side of leaf blade

  0

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Massachusetts
  • New Hampshire
  • Vermont

  Specific habitat

  • cliffs, balds, or ledges
  • shores of rivers or lakes
  • woodlands

• 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
  • 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

Not classified

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae