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Native Plant Trust: Go Botany Discover thousands of New England plants

Nabalus trifoliolatus — three-leaved rattlesnake-root

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Facts

Three-leaved rattlesnake-root is distributed throughout New England, but in alpine areas of northern New England it can have a dwarfed form with deeply divided leaves. This form is probably just an adaptation to the harsher environmental conditions rather than a separate species or variety. The very young basal leaves and the newly-emerged shoot are edible.

Habitat

Alpine or subalpine zones, cliffs, balds, or ledges, forests, mountain summits and plateaus, woodlands

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
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Leaf type
  • leaves are compound (made up of two or more discrete leaflets)
  • 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 lobes, or it has both teeth and lobes
  • the edge of the leaf blade has no teeth or lobes
  • 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
  • green to brown
  • white
  • 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
30–120 mm
Disk flower number
0
Show all characteristics

  • Flowers

    Bases of bract appendages
    NA
    Bract cycle number
    there is one main cycle of bracts
    Bract inner side hairs
    the bracts are not hairy on their inner surfaces
    Bract margins
    • there are few or no fine hairs along the bract margins
    • there are fine hairs along the bract margins
    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 elliptic (widest near the middle and tapered towards the base and tip)
    • the main bracts are lanceolate (widest above the base, then taper narrowly towards the tip)
    • the main bracts are of a different shape than the given options
    • the main bracts are ovate (egg-shaped)
    Bract tip shape
    the tips of the bracts acute (have a sharp point)
    Disk flower color
    NA
    Disk flower lobe number
    0
    Disk flower number
    0
    Disk flower proportions
    NA
    Disk flower reproductive parts
    NA
    Disk flower shape
    NA
    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 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
    10–13 mm
    Inflorescence branching (Solidago)
    NA
    Inflorescence shape
    the inflorescence is not flat-topped but appears rounded, with some flower heads distinctly higher than others
    Number of bracts at flower head base
    7–10
    Ovary beak
    there is no beak on the ovary
    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 lines or ribs
    • there are seven to nine ribs visible on the ovary
    • there are ten or more ribs visible on the ovary
    Ovary surface
    the ovary surface has no points, bumps or wrinkles, though it may have lines, ribs or wings
    Ray flower color
    • green to brown
    • white
    • yellow
    Ray flower reproductive parts
    the ray flowers have both carpels and stamens
    Ray flowers
    • 11-15
    • 6-10
    Ray length
    9–15 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 a cycle of much smaller bracts outside the cycle of larger and longer bracts
    Style branch number
    there are no obvious branches on the style
    Swelling at base of flower head
    the peduncles are not swollen, or only slightly
    Width of flower head base
    4–5 mm

  • Fruits or seeds

    Ovary beak length
    0 mm
    Ovary length in developed fruit
    4–5 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
    7–9 mm
    Seed hair tuft tips
    the pappus hairs are slender
    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 no glandular (translucent) dots or scales
    Sap
    the sap is milky and opaque, and may be white or colored

  • 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
    there is a thickened taproot 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 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
    Leaf blade base shape
    • the base of the leaf blade is rounded
    • the base of the leaf blade is truncate (ends abruptly in a more or less straight line as though cut off)
    • the base of the leaf is cordate (heart-shaped) or sagittate (arrow-shaped)
    Leaf blade bloom
    there is a noticeable powdery or waxy bloom on the underside of the leaf
    Leaf blade edges
    • the edge of the leaf blade has lobes, or it has both teeth and lobes
    • the edge of the leaf blade has no teeth or lobes
    • the edge of the leaf blade has teeth
    Leaf blade length
    30–120 mm
    Leaf blade shape
    • the leaf blade is ovate (widest below the middle and broadly tapering at both ends)
    • the leaf blade is triangular, with the stalk or attachment point on one of the sides
    Leaf blade surface colors
    there is no noticeable color variation on the upper surface of the leaf
    Leaf blade width
    10–150 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 leaf stalks
    Leaf stalk length
    10–250 mm
    Leaf tip extension
    NA
    Leaf type
    • leaves are compound (made up of two or more discrete leaflets)
    • leaves are simple (i.e., lobed or unlobed but not separated into leaflets)
    Specific leaf type
    • the leaf has lobes that radiate from the base, somewhat like a hand
    • the leaf is compound, there are two or more discrete leaflets
    • the leaves are simple (i.e., lobed or unlobed but not separated into leaflets

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • alpine or subalpine zones
    • cliffs, balds, or ledges
    • forests
    • mountain summits and plateaus
    • woodlands

  • Scent

    Plant odor
    the plant does not have much of an odor

  • 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 bloom
    • the stem has a powdery or waxy film on it that can be rubbed away
    • there is no powdery or waxy film on the stem
    Stem internode hair direction
    NA
    Stem internode hair length
    0 mm
    Stem internode hair type
    the stem has no hairs between the nodes
    Stem internode hairs
    the stem has no hairs between the nodes
    Stem wings
    the stem does not have wings on it

Wetland status

Not classified

In New England

Distribution

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

Conservation status

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

Massachusetts
widespread (S-rank: S5)
Vermont
uncommon (S-rank: S3)

From Flora Novae Angliae dichotomous key

6.  Nabalus trifoliolatus Cass. N

three-leaved rattlesnake-root. Nabalus nanus (Bigelow) DC.; Prenanthes alba L. var. nana Bigelow; P. nana (Bigelow) Torr. ex DC.; P. trifoliolata (Cass.) Fern.; P. trifoliolata (Cass.) 
Fern. var. nana Bigelow • CT, MA, ME, NH, RI, VT. Forests, woodlands, cliffs, ravines, open mountain tops, coastal headlands and islands. Nabalus nanus has been variously treated 
as a distinct species or variety with limited distribution in northeastern North America. The dark involucral bracts of N. nanus are not diagnostic; specimens of N. trifoliolatus from exposed habitats (e.g., subalpine areas, downeast coastal islands) also possess them. Plant size has also been used to distinguish taxa, but this is certainly a function of environment, 
and northern specimens of N. trifoliolatus from Quebec and Labrador intergrade with 
 N. nanus. Milstead (1964) arbitrarily designated alpine plants as N. nanus and dismissed the intermediate material as N. trifoliolatus. Field observations on Katahdin in central Maine 
show that N. trifoliolatus demonstrates clinal changes in morphology correlated with elevation (i.e., lower elevation plants resemble typical N. trifoliolatus and plants gradually change toward N. nanus with increased elevation). Based on this evidence, N. nanus is 
here treated as a taxonomic synonym of N. trifoliolatus.

4×6. Nabalus racemosus × Nabalus trifoliolatus → Nabalus ×‌mainensis (Gray) Heller is a rare hybrid known from only northern Maine river shores within New England. It ± resembles N. racemosus vegetatively (including the clasping upper stem leaves), but the basal leaf blades are more abruptly contracted to a petiole-like base, and the involucral bracts are glabrous (as in N. trifoliolatus).

Native to North America?

Yes

Sometimes confused with

Nabalus altissimus:
each flower head with 5 or 6 flowers and 4-6 longer involucral bracts (vs. N. trifoliolatus, with each flower head with 9-20 flowers and 7-14 longer involucral bracts).
Nabalus boottii:
rays white, axis of capitulescence and often upper portion of stem villous-puberulent, and lower leaf blades simple, triangular-sagittate (vs. N. trifoliolatus, with rays green-yellow to yellow-white, axis of capitulescence and stem glabrous, and lower leaf blades pinnately or palmately lobed).

Synonyms

  • Nabalus nanus (Bigelow) DC.
  • Prenanthes alba L. var. nana Bigelow
  • Prenanthes nana (Bigelow) Torr. ex DC.
  • Prenanthes trifoliolata (Cass.) Fern.
  • Prenanthes trifoliolata (Cass.) Fern. var. nana Bigelow

Family

Asteraceae

Genus

Nabalus