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Hieracium robinsonii — Robinson's hawkweed

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Facts

Robinson's hawkweed is a globally imperiled species, reduced to a single population in northern New Hampshire and a handful in northeastern Canada, although it could be rediscovered in northern Maine. It is confined to open ledges and cliffs along rivers, usually on high-pH bedrock.

Habitat

Shores of rivers or lakes

New England distribution

Adapted from BONAP data

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North America distribution

Adapted from BONAP data

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Characteristics

Habitat
terrestrial
New England state
  • Maine
  • New Hampshire
Leaf type
leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
Leaf arrangement
alternate: there is one leaf per node along the stem
Leaf blade edges
the edge of the leaf blade has teeth
Flower type in flower heads
the flower head has ray flowers only, meaning all of the individual flowers of the flower head have a strap-shaped ray, which may or may not have teeth at the very tip of the ray
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
20–80 mm
Disk flower number
0
Show all characteristics

  • Flowers

    Bract cycle number
    there are two main cycles of bracts
    Bract outer side hair type
    the bracts are hairy on their outer surfaces, with hairs having glands (a swelling at the tip of the hair)
    Bract outer side hairs
    the bracts are hairy on their outer surfaces
    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)
    Disk flower number
    0
    Disk flower proportions
    NA
    Disk flower reproductive parts
    NA
    Disk flower shape
    NA
    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 profile
    the disk is flat or nearly flat across the top
    Flower type in flower heads
    the flower head has ray flowers only, meaning all of the individual flowers of the flower head have a strap-shaped ray, which may or may not have teeth at the very tip of the ray
    Height of flower head base
    10–15 mm
    Inflorescence shape
    the inflorescence is flat-topped in profile
    Ovary cross-section
    the ovary has five or more corners in cross-section
    Ovary hair type
    the ovary has no hairs on it
    Ovary hairs
    the ovary has no hairs on it
    Ovary profile
    in profile, the ovary is another shape
    Ray flower color
    yellow
    Ray flower reproductive parts
    the ray flowers have both carpels and stamens
    Ray flowers
    26-50
    Reproductive system
    NA

  • Fruits or seeds

    Ovary length in developed fruit
    3–5 mm
    Seed hair tuft color
    • the pappus hairs are tan to dark brown
    • the pappus hairs are white or off-white
    Seed hair tuft details
    the pappus hairs are hooked or barbed
    Seed hair tuft length
    4.5–7 mm
    Tuft or plume on fruit
    at least a part of the plume is made up of fine bristles

  • Growth form

    Growth form
    the plant has one or more free-standing stems
    Horizontal rooting stem
    there are no stolons
    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
    there is a thickened taproot on the plant

  • Leaves

    Hairs on underside of leaf blade
    the underside 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
    Leaf blade edges
    the edge of the leaf blade has teeth
    Leaf blade length
    20–80 mm
    Leaf blade shape
    • 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)
    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 width
    7–20 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 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
    • Maine
    • New Hampshire
    Specific habitat
    shores of rivers or lakes

  • Stem, shoot, branch

    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
    at least some of the hairs on the stem have glands
    Stem internode hairs
    the stem has hairs between the nodes

Wetland status

Not classified

In New England

Distribution

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

Conservation status

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

Maine
extremely rare (S-rank: S1), endangered (code: E)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)

From Flora Novae Angliae dichotomous key

13.  Hieracium robinsonii (Zahn) Fern. NC

Robinson’s hawkweed. Hieracium ungavense Lepage • ME, NH; northern portion of states. 
River shore outcrops, usually of high pH.

Native to North America?

Yes

Sometimes confused with

Hieracium maculatum:
leaf blades 15–50 mm wide, peduncles stipitate-glandular, and plants 30–100 cm tall (vs. H. robinsonii, with leaf blades 7–20 mm wide, peduncles lacking stipitate glands, and plants 10–35 cm tall).

Synonyms

  • Hieracium ungavense Lepage

Family

Asteraceae

Genus

Hieracium