Your help is appreciated. We depend on donations to help keep this site free and up to date for you. Can you please help us?

Donate

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

Asclepias tuberosa — butterfly milkweed

Copyright: various copyright holders. To reuse an image, please click it to see who you will need to contact.

Facts

Butterfly milkweed is very rare in New England, and protected in most states. This is a very recognizable species, differing from other milkweeds by having alternate leaves, yellow-orange flowers, and having clear rather than milky latex. The Iroquois rubbed their legs and running shoes with a poultice of the smashed roots to give them running strength. The Omaha ate the raw root to treat bronchial and pulmonary conditions. And the Cherokee used the fibers to fashion belts.

Habitat

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

New England distribution

Adapted from BONAP data

Found this plant? Take a photo and post a sighting.

North America distribution

Adapted from BONAP data

enlarge

Characteristics

Habitat
terrestrial
New England state
  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont
Flower petal color
  • orange
  • pink to red
  • yellow
Leaf type
the leaves are simple (lobed or unlobed but not separated into leaflets)
Leaf arrangement
whorled: there are three or more leaves per node along the stem
Leaf blade edges
the edge of the leaf blade is entire (has no teeth or lobes)
Flower symmetry
there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
Number of sepals, petals or tepals
there are five petals, sepals, or tepals in the flower
Fusion of sepals and petals
the petals or the sepals are fused into a cup or tube
Stamen number
5
Fruit type (general)
the fruit is dry and splits open when ripe
Fruit length
80–120 mm
Show all characteristics

  • Clonal plantlets

    Bulbils
    the plant does not appear to have bulbils
    Bulblets replace flowers
    there are no bulblets where the flowers are located

  • Flowers

    Anther opening
    the anthers have some other type of opening
    Calyx symmetry
    there are two or more ways to evenly divide the calyx (the calyx is radially symmetrical)
    Carpels fused
    the carpels are fused to one another
    Cleistogamous flowers
    there are no cleistogamous flowers on the plan
    Corolla palate
    no
    Epicalyx
    the flower does not have an epicalyx
    Epicalyx number of parts
    0
    Filament surface
    the filament is smooth, with no hairs or scales
    Flower description
    the flower has a superior ovary, and lacks a hypanthium
    Flower petal color
    • orange
    • pink to red
    • yellow
    Flower symmetry
    there are two or more ways to evenly divide the flower (the flower is radially symmetrical)
    Flowers sunken into stem
    no
    Form of style
    the flower has two or more completely separate styles
    Fusion of sepals and petals
    the petals or the sepals are fused into a cup or tube
    Horns in hoods (Asclepias)
    the corona horns are shorter than, or equal in length to, the corona hoods
    Hypanthium
    the flower does not have a hypanthium
    Inflorescence one-sided
    the flowers are arrayed in a spiral around the inflorescence axis or branches, or occur singly, or in several ranks
    Inner tepals (Rumex)
    NA
    Nectar spur
    the flower has no nectar spurs
    Number of sepals, petals or tepals
    there are five petals, sepals, or tepals in the flower
    Number of styles
    2
    Ovary position
    the ovary is above the point of petal and/or sepal attachment
    Petal and sepal arrangement
    the flower includes three distinct cycles of petal- or sepal-like structures
    Petal and sepal colors
    • orange
    • pink to red
    • yellow
    Petal appearance
    the petals are thin and delicate, and pigmented (colored other than green or brown)
    Petal folds or pleats
    the petals of the flower do not have folds or plaits
    Petal hairs (Viola)
    NA
    Petal number
    5
    Petal tip shape
    • the petal tip is acute (sharply pointed)
    • the petal tip is obtuse (bluntly pointed)
    Petal tips (Cuscuta)
    NA
    Reproductive system
    all the flowers have both carpels and stamens (synoecious)
    Scales inside corolla
    no
    Sepal and petal color
    the sepals are different from the petals
    Sepal appendages
    the sepals do not have appendages on them
    Sepal appendages (Oenothera)
    NA
    Sepal number
    5
    Stamen attachment
    • the stamens are attached at or near the bases of the petals or tepals
    • the stamens are attached at or near the bases of the petals or tepals
    Stamen number
    5
    Stamen position relative to petals
    the stamens are lined up with the petals
    Staminodes
    there are no staminodes on the flower
    Umbel flower reproductive parts
    NA
    Upper lip of bilabiate corolla
    NA

  • Fruits or seeds

    Achene relative orientation
    NA
    Achene shape
    NA
    Achene surface (Polygonum)
    NA
    Achene type
    NA
    Berry color
    NA
    Capsule color (Viola)
    NA
    Capsule ribs
    NA
    Capsule splitting
    NA
    Fruit (pyxis) dehiscence
    NA
    Fruit beak length
    0 mm
    Fruit cross-section
    the fruit is round in cross-section
    Fruit features (Brassicaceae)
    NA
    Fruit length
    80–120 mm
    Fruit locules
    one
    Fruit type (general)
    the fruit is dry and splits open when ripe
    Fruit type (specific)
    the fruit is a follicle (has one ovary that splits along one side to release the seeds)
    Legumes (Fabaceae)
    NA
    Mericarp segment shape (Desmodium)
    NA
    Other markings on berry
    NA
    Ovary stipe
    the ovary or fruit does not have a stipe
    Placenta arrangement
    the plant has parietal placentation, where ovules develop on the wall or slight outgrowths of the wall forming broken partitions within a compound ovary
    Rows of seeds in fruit (Brassicaceae)
    NA
    Schizocarpic fruit compression
    NA
    Schizocarpic fruit segments
    0
    Septum in fruit (Brassicaceae)
    NA
    Wings on fruit
    the fruit does not have wings on it
    prickles on fruits
    the fruits do not have thorn-like defensive structures

  • Glands or sap

    Glands on leaf blade
    the leaf blades do not have glandular dots or scales
    Sap
    the sap is clear and watery
    Sap color
    the sap is clear

  • Growth form

    Horizontal rooting stem
    the plant does not have stolons
    Lifespan
    the plant lives more than two years
    Parasitism
    the plant is not parasitic
    Plant color
    the leaves or young stems of the plant are green
    Plants darken when dry
    no
    Spines on plant
    the plant has no spines

  • Leaves

    Bracteole number (Apiaceae)
    0
    Bracts in plantain (Plantago)
    NA
    Final leaf segment length (compound lvs only)
    0 mm
    Final leaf segment length to width ratio (compound lvs only)
    0
    Hairs on underside of leaf
    the underside of the leaf is not hairy, or it has very few hairs
    Leaf arrangement
    whorled: there are three or more leaves per node along the stem
    Leaf blade base shape
    • the base of the leaf blade is cordate (heart-shaped, has rounded lobes at the base)
    • the base of the leaf blade is cuneate (wedge-shaped, tapers to the base with relatively straight, converging edges), or narrow
    • the base of the leaf blade is hastate (halberd-shaped, with outward-pointing basal lobes)
    • the base of the leaf blade is rounded
    Leaf blade edges
    the edge of the leaf blade is entire (has no teeth or lobes)
    Leaf blade length
    50–100 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 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)
    • the leaf blade is obovate (egg-shaped, but with the widest point above the middle of the leaf blade)
    • the leaf blade is triangular, with the stalk or attachment point on one of the sides
    Leaf blade surface colors
    the upper side of the leaf blade is relatively uniform in color
    Leaf blade vein pattern
    the major veins of the leaf blade branch, but do not rejoin
    Leaf duration
    the leaves drop off in winter (or they whither but persist on the plant)
    Leaf form
    the leaves are green, with an expanded blade and a leaf-like texture
    Leaf spines
    there are no spines on the leaf edges
    Leaf stalk attachment to leaf
    the petiole attaches at the basal margin of the leaf blade
    Leaf stalk base
    the petiole base is narrow where it attaches to the stem
    Leaf type
    the leaves are simple (lobed or unlobed but not separated into leaflets)
    Leaf types
    There is a gradual change in appearance of the leaves from the base (or near the base) of the plant to those from further up on the stem, with leaves progressively changing as one moves higher on the stem (often becoming shorter, or less toothed/lobed, and/or with shorter petioles).
    Leaf variation
    the leaves are nearly similar in size, prominence of teeth, and length of stalks throughout the stem
    Leaflet number
    0
    Leaflet petiolules
    NA
    Leaves per node
    • there are five leaves per node along the stem
    • there are four leaves per node along the stem
    • there are six leaves per node along the stem
    • there are three leaves per node along the stem
    Pinnately compound leaf type
    NA
    Specific leaf type
    the leaves are simple (lobed or unlobed but not separated into leaflets)
    Stipels
    NA
    Stipule features
    NA
    Stipules
    there are no stipules on the plant

  • Place

    Habitat
    terrestrial
    New England state
    • Connecticut
    • Maine
    • Massachusetts
    • New Hampshire
    • Rhode Island
    • Vermont
    Specific habitat
    • grasslands
    • man-made or disturbed habitats
    • meadows or fields

  • Stem, shoot, branch

    Branched tendrils
    NA
    Hairs between stem nodes
    the hairs on the stem are plain, without glands or branches, and not tangled
    Hooked hairs on stem between nodes
    no
    Leaves on stem
    there is at least one full leaf above the base of the flowering stem
    Plant height
    30–70 cm
    Stem roughness between nodes
    the stem does not feel rough
    Tendril origin
    NA
    Tendrils
    the plant does not have tendrils

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.

Maine
extirpated (S-rank: SX), potentially extirpated (code: PE)
Massachusetts
fairly widespread (S-rank: S4), #NAME? (code: #NAME?)
New Hampshire
extremely rare (S-rank: S1), endangered (code: E)
Rhode Island
rare (S-rank: S2), concern (code: C)
Vermont
historical (S-rank: SH), threatened (code: T)

ssp. interior

Massachusetts
unranked (S-rank: SNR)

ssp. tuberosa

Massachusetts
unranked (S-rank: SNR)

From Flora Novae Angliae dichotomous key

7.  Asclepias tuberosa L. NC

butterfly milkweed. 7a. Asclepias tuberosa L. var. interior (Woods.) Shinners • CT, MA, ME, NH, 
 RI, VT. Dry fields, sand plains, roadsides, disturbed areas.

1a.  Leaf blades narrow-oblong to lanceolate or oblong-ovate, widest below the middle, 
± truncate to cordate at the base, gradually tapering to the apex

… 7a. Asclepias tuberosa ssp. interior Woods.

1b.  Leaf blades oblong to obovate or oblanceolate, broadest above the middle, cuneate to rounded at the base, abruptly tapering to the apex … 7b. Asclepias tuberosa ssp. tuberosa

Subspecies interior is known from CT and is of conservation concern. Subspecies tuberosa is known from CT, MA, ME, NH, RI, VT.

Native to North America?

Yes

Family

Apocynaceae

Genus

Asclepias