Oligoneuron rigidum (L.) Small

stiff flat-topped-goldenrod

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New England Distribution

Adapted from BONAP data

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North America Distribution

Adapted from BONAP data

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Facts About

Stiff flat-topped-goldenrod reaches the edge of its natural range in New England, where it is very rare, occurring historically in Massachusetts and Rhode Island, and currently found in only a few populations in Connecticut, on limestone ledges and on dry, sandy and rocky soils near the coast. Its flowering heads are large and few, compared to those of other goldenrod species. The main threats to New England populations include shading and competition from other plant species, and browsing by white-tailed deer.

Habitat

Forest edges

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Massachusetts
  • Rhode Island
Leaf type
leaves are simple (lobed or unlobed but not separated into leaflets)
Leaf arrangement
  • alternate: there is one leaf per node along the stem
  • the leaves are growing only at the base of the plant (basal)
Leaf blade edges
the edge of the leaf blade has teeth
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
Ray flower color
yellow
Tuft or plume on fruit
at least a part of the plume is made up of fine bristles
Spines on plant
the plant has no spines
Leaf blade length
60–300 mm
Flower head width
anything
Disk flower number
  • 11-20
  • 21-50
Show All Characteristics
  • Flowers
    Bract cycle number
    there are three or more cycles of bracts
    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 oblong (roughly rectangular but rounded at the ends)
    Bract spines
    the bracts have no spines
    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 are rounded
    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
    • 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 abruptly widened at some point below the lobes
    Disk width
    5–10 mm
    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, 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 rounded across the top
    Flower head shape
    the sides of the flower head are roughly parallel, like a cylinder
    Flower head width
    anything
    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
    6–8 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
    • the stem of the inflorescence is not hairy
    Number of bracts at flower head base
    10–35
    Ovary beak
    there is no beak on the ovary
    Ovary cross-section
    • the ovary has five or more corners in 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 ten or more ribs visible on the ovary
    Ovary profile
    in profile, the ovary is another shape
    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
    3–15 mm
    Peduncle orientation
    the flower heads are held upright, or slightly angled outwards
    Ray flower color
    yellow
    Ray flower reproductive parts
    the ray flowers have carpels or stamens, but not both
    Ray flowers
    • 11-15
    • 6-10
    Ray length
    3–5 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
    Width of flower head base
    5–7 mm
  • Fruits or seeds
    Number of pappus parts
    11 or more
    Ovary length in developed fruit
    0.7–1.7 mm
    Seed hair tuft details
    the pappus hairs are hooked or barbed
    Seed hair tuft length
    3–4 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
    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 caudex (the root mass is firm and hardened at the top)
    • 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
    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
    • the leaves are growing only at the base of the plant (basal)
    Leaf blade base
    • the leaf has a distinct petiole
    • the leaf has no petiole
    • the leaf has no petiole and at the base it clasps the stem, or goes all the way around the stem so the stem appears to pierce the leaf
    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 flatness
    the leaf is flat (planar) at the edges
    Leaf blade hairs
    the leaf blade has simple hairs with no glands, and not tangled or wooly
    Leaf blade length
    60–300 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 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)
    • the tip of the leaf blade is obtuse (bluntly pointed)
    Leaf blade veins
    the leaf blade has one main vein running from the base towards the tip
    Leaf blade width
    15–100 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
    • the leaves have no leaf stalks, but attach directly to the stem
    Leaf tufts in axils
    there are no clusters of smaller leaves
    Leaf type
    leaves are simple (lobed or unlobed but not separated into leaflets)
    Leaflet number
    0
    Specific leaf type
    the leaves are simple (lobed or unlobed but not separated into leaflets
  • Place
    Habitat
    terrestrial
    New England state
    • Connecticut
    • Massachusetts
    • Rhode Island
    Specific habitat
    edges of forests
  • 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
    Stem internode hairs
    the stem has hairs between the nodes

Wetland Status

Not classified

New England Distribution and Conservation Status

Distribution

Connecticut
present
Maine
absent
Massachusetts
present
New Hampshire
absent
Rhode Island
present
Vermont
absent

Conservation Status

Exact status definitions can vary from state to state. For details, please check with your state.

Connecticut
extremely rare (S-rank: S1), endangered (code: E)

var. rigidum

Rhode Island
historical (S-rank: SH), state historical (code: SH)

Native to North America?

Yes

Family

Asteraceae

Genus

Oligoneuron

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