Whorled milkweed

Appalachian-Blue Ridge forests

Arizona Mountains forests

Atlantic coastal pine barrens

Blue Mountains forests

Central Pacific Northwest coastal forests

Central Tallgrass prairie

Central-Southern Cascades Forests

Pollination

Self-fertile

Self-fertile in mechanism but, like all Asclepias, dependent on specialized pollination by larger insects. The pollen is packaged in paired pollinia that hook onto the legs of visiting bees, wasps, and butterflies and are carried to the next flower; without those visitors seed set is poor. The small greenish-white umbels are readily worked by honeybees, bumblebees, and small wasps for their late nectar.

Plants don't grow alone

Larval host

Specialist

Butterfly

Monarch butterfly (Danaus plexippus)

Larvae feed only on milkweeds (Asclepias spp.). Whorled milkweed is a genuine monarch host across the prairies and dry open ground of central and eastern North America, and its late bloom also feeds migrating adults; the caterpillars sequester the plant's cardiac glycosides as a predator deterrent.

Larval host

Specialist

Moth

Milkweed tussock moth (Euchaetes egle)

Milkweed tussock moth (Euchaetes egle) larvae are Asclepias specialists that share milkweed plants with monarchs, sequestering the same cardiac glycosides for chemical defense.

Pollinates

Bee

Common eastern bumblebee (Bombus impatiens)

Bumblebees are among the larger insects strong enough to work the pollinia-loaded flowers; the Wildflower Center flags the species as of special value to bumble bees.

Nectar forage

Bee

European honeybee (Apis mellifera)

The Lady Bird Johnson Wildflower Center flags whorled milkweed as of special value to honey bees; its late-summer umbels are a useful nectar source when many prairie plants have finished.

For people

Toxic - do not consume

All parts contain cardiac glycosides (cardenolides) and resinoids and are toxic if eaten. Whorled milkweed is not a foraging plant: unlike common milkweed (Asclepias syriaca), the narrow-leaved whorled milkweeds are among the more poisonous milkweeds to grazing livestock, and the plant keeps its toxicity even when dried in hay, so it is a genuine hazard in pastures and hayfields. The milky sap can also irritate skin, and the plant is toxic to cats, dogs, and horses. The same cardenolides are what monarch caterpillars sequester from the sap to make themselves distasteful to predators.

Toxic parts

leaves, stems, sap, roots

Similar plants

Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.

Zizia aurea

Golden alexanders

A clump-forming native perennial of the carrot family that opens flat-topped, compound umbels of tiny golden-yellow flowers in late spring, when little else is blooming. The toothed, twice-divided-in-threes (biternate) foliage and the bare central flower stalk on each umbel set it apart from other umbellifers. A documented larval host for the black swallowtail and an early-season nectar and pollen source for short-tongued native bees.

Short-toothed mountain mint

A clump-forming aromatic native perennial of eastern North America, grown as much for its silvery floral bracts as its bloom - the upper leaves below each flower head turn a frosted, dusty-mint color in summer. Dense flat-topped clusters of tiny two-lipped pinkish-white flowers cover the plant from mid to late summer and are a magnet for bees and butterflies. Unlike the true mints (Mentha), it spreads only modestly by rhizome and is not invasive.

Full sun / Part sun / Part shade

Coreopsis verticillata

Threadleaf coreopsis

A native eastern North American perennial with fine threadlike foliage and abundant bright-yellow daisy flowers from early summer through fall. Drought-tolerant + long-blooming; among the most reliable native sunny-border perennials. The Moonbeam cultivar is the most-planted form.

A native eastern North American clump-forming perennial with palmately-lobed foliage and clustered pink-to-purple five-petaled spring flowers. Among the most reliable native woodland perennials for cool-moist sites; tolerates a wide range of conditions and slowly naturalizes by self-seeding.

The native sundial lupine of eastern North American sand barrens and oak savannas - erect 1-2.5-foot stems carry showy spring spikes of blue, pea-shaped flowers above palmately divided leaves of 7-11 radiating leaflets. A nitrogen-fixing legume of dry, sandy, acidic soils, it is the sole larval host for the federally endangered Karner Blue butterfly and the Frosted Elfin, and carries the Xerces Society "special value to native bees and bumble bees" flag.

A drought-hardy western-native subshrub (long known as Zauschneria) that lights up dry, rocky ground with scarlet tubular flowers from midsummer until frost - exactly when migrating and resident hummingbirds need a late-season nectar source. Slender, highly-branched stems carry small grey-green lance-shaped leaves; the whole plant thrives on full sun, lean soil, and very little water once established.