Whorled milkweed

Asclepias verticillata

Asclepias verticillata holds immense significance as a valuable native host plant for Monarch caterpillars. It also serves as a crucial source of late-season nectar for adult Monarchs. However, the Monarchs don’t have the flowers entirely to themselves. A diverse array of butterflies, bees, and other insects can be seen visiting the busy blooms. It’s truly a delightful experience to spend even a few minutes observing the varied insect activity!


  1. NAME
  2. BLOOM
  3. POLLINATORS
  4. DESCRIPTION
  5. PLANTS GROWING NEARBY
  6. HABITAT
  7. CONSERVATION STATUS
  8. INTERESTING TIDBITS

This perennial forb, scientifically known as 'Asclepias,' is named after the Greek god of medicine, Asklepios, reflecting its historical medicinal use. It is commonly referred to as Whorled milkweed. The Latin botanical term 'verticillata' means 'whorled' and describes the plant's distinctive leaf arrangement, where the leaves form rings around the stem.

The straightforward common name, Whorled milkweed, further emphasizes this distinctive feature.


Flowers arise from the axils of the middle to upper leaves. Initially, the tiny buds may have a reddish, pink or green hue.

  • Green and pinkish buds
    Green and pinkish buds
  • Close look at pinkish buds
    Close look at pinkish buds

The flowers occur in umbels on short stalks (peduncles). The umbels contain anywhere from 6-20 individual, bright white flowers. Blooming proceeds from the base to the top of the plant.

  • Buds at the top of the plant
    Buds at the top of the plant
  • Umbels of white flowers
    Umbels of white flowers
  • Flowering from base to top
    Flowering from base to top
  • Spent flowers at base
    Spent flowers at base

Whorled milkweed is a drought-tolerant perennial plant growing up to 2 feet. It is typically unbranched. The stem is pubescent with short hairs. The narrow leaves typically occur in whorls of 3-6 and dangle downward. They are sessile or may have short petioles.

  • Leaves, flowers, buds
    Leaves, flowers, buds
  • Stem and leaves
    Stem and leaves
  • Pubescent stem
    Pubescent stem
  • Developing seed pods
    Developing seed pods

Like all milkweeds, the seed pods split open when ripe, releasing tufts of cottony seeds that are dispersed by wind.


Whorled milkweed is an excellent choice for a pollinator garden because it supports a diverse range of insects, including various bees, butterflies, moths, and wasps. Monarch caterpillars are commonly found on Asclepias verticillata. The photos below depict Monarch caterpillars diligently munching on the leaves of Whorled milkweed (the second photo shows two!).

  • Monarch caterpillar
  • Two Monarch caterpillars

In addition to Monarch butterflies, I’ve observed Juniper hairstreaks and Common buckeye butterflies nectaring on the flowers of Whorled milkweed.

  • Juniper hairstreak
    Juniper hairstreak
  • Common buckeye
    Common buckeye

In addition to Monarch butterflies, Whorled milkweed is a host plant for Cycnia tenera, the delicate cycnia moth, also known as the dogbane tiger moth.

Delicate Cycnia moth
Delicate Cycnia moth

Several bees and wasps can also be found visiting these flowers.

  • Augochloropsis bee
    Augochloropsis bee
  • Genus Euroynerus wasp
    Genus Euroynerus wasp
  • Genus Pepsis (New World Tarantula-hawk wasp)
    Genus Pepsis (New World Tarantula-hawk wasp)
  • Genus Pepsis (New World Tarantula-hawk wasp)
    Genus Pepsis (New World Tarantula-hawk wasp)

Other interesting insect visitors I’ve observed are shown below.

  • Secondary Screwworm Fly
    Secondary Screwworm Fly
  • Oncopeltus fasciatus (Large milkweed Bug)
    Oncopeltus fasciatus (Large milkweed Bug)

You’ll discover a diverse array of native wildflowers blooming near Whorled milkweed. Among my favorites are Senna marilandica, Rudbeckia grandiflora, Houstonia longifolia, and the beautiful grass, Sideoats grama. For more common companions, refer to the Growing Nearby section above.

  • with Senna marilandica
    with Senna marilandica
  • with Rudbeckia grandiflora
    with Rudbeckia grandiflora
  • with Sideoats gramma
    with Sideoats gramma
  • with Houstonia longifolia
    with Houstonia longifolia

Whorled milkweed favors dry prairie or grassland habitat, but is also found in glades, open woods and woodland edges.

  • Grassland habitat
    Grassland habitat
  • Glade habitat
    Glade habitat

In Arkansas, Asclepias verticillata has a Conservation value of 8 in the group of 8-10, meaning ‘Conservative taxa with strong fidelity to intact habitats. These taxa tend to exhibit late-successional characteristics like long lifespans with low seed sets and an inability for far ranging dispersal’.

Natureserve lists it overall as G5 Secure. It is native from Montana and New Mexico to the East coast. While most states show ‘No Status Rank’, it is documented as follows-

Critically Imperiled- Rhode Island, Vermont

Imperiled- Massachusetts, New Jersey, New York, Pennsylvania

Vulnerable- Maryland, West Virginia, Montana

Apparently Secure- Virginia, Kentucky, Florida

Secure/Apparently Secure- Indiana, Iowa, Kansas, North Carolina

Possibly Extirpated- Delaware

All other states within its range have no status ranking on Natureserve.


While all milkweeds contain cardiac glycosides that are toxic to livestock and other animals (including pets), this milkweed has one of the highest concentrations. Of course, this helps to deter deer and rabbits from bothering this pretty wildflower!