Longleaf milkweed

Pictured above: Longleaf milkweed (Asclepias longifolia) by Emily Bell. Click on terms for botanical definitions. View post as a PDF.

Longleaf milkweed is a deciduous perennial wildflower that occurs naturally in bogs, moist to wet flatwoods and prairies. It typically blooms in spring but may bloom well into summer or early fall.

Longleaf milkweed flowers are born in axillary or terminal umbels. Each flower bears a five-lobed calyx and five-lobed corolla, both of which are whitish-green with purple tips. Calyx lobes are reflexed. Leaves are long (up to 6 inches), linear to narrowly lanceolate (up to 3/8-inch wide) and sessile. They have small hairs scantly distributed along margins, over the upper surface and along veins of the lower surface. Leaves may be oppositely or alternately arrangedStems are slender, rigid and slightly pubescentSeeds are born in erect, smooth follicles that measure 3½ inches or longer.

Longleaf milkweed blooms and leaves. Photo by Eleanor Dietrich
Longleaf milkweed flowers. Photo by Emily Bell

The genus Asclepias is named for Asclepius, the Greek god of healing. The species epithet longifolia literally translates to “long leaf,” hence the common name.

Like all members of the Asclepias genus, Longleaf milkweed is a larval host plant for Monarch, Queen and Soldier butterflies. The plant contains a milky latex that is toxic to most animals, but Monarch, Queen and Soldier caterpillars are adapted to feed on them despite the chemical defense. Learn more about Monarchs and Milkweed in Florida here. The flowers are an important nectar source for bees and wasps.

Family: Apocynaceae (Dogbane family)
Native range: Panhandle west of Jefferson County, western peninsula from Citrus south to Monroe and Miami-Dade counties, and eastern peninsula from Seminole north to Nassau counties
To see where natural populations of Longleaf milkweed have been vouchered, visit florida.plantatlas.usf.edu.
Lifespan: Perennial
Soil: Moist to wet soils
Exposure: Full sun to minimal shade
Growth habit: Up to 28”

Longleaf milkweed is not commercially available. Visit a natural area to see it.

For information on other Asclepias species, see these resources:

Clasping milkweed

Clasping milkweed (Asclepias amplexicaulis) is a late spring- through summer- blooming milkweed that occurs in dry sandy areas from sandhills to pine savannahs, open woodlands and fallow fields.
Read more… Clasping milkweed

Florida milkweed

Florida milkweed (Asclepias feayi) is a dainty endemic at home in the sandhills and scrubby flatwoods of Central and South Florida. It emerges from winter dormancy in spring and typically blooms mid-summer.
Read more… Florida milkweed

Fewflower milkweed

Fewflower milkweed (Asclepias lanceolata) is a delicate wildflower found in swamps and moist to wet pinelands and prairies throughout Florida. Its stunning orange flowers typically bloom late spring through fall.
Read more… Fewflower milkweed

Swamp milkweed

Swamp milkweed (Asclepias perennis) blooms in late spring through early fall and attracts many pollinators. It is a larval host plant for Monarch, Queen and Soldier butterflies.
Read more… Swamp milkweed
Hummingbird clearwing (Hemaris thysbe) on Swamp milkweed, Asclepias incarnata

Swamp milkweed

Swamp milkweed (Asclepias incarnata ) has showy pink flowers that typically bloom in summer and attract many pollinators. It occurs naturally in floodplain swamps, hydric hammocks, wet pine flatwoods and marshes.
Read more… Swamp milkweed
Savannah milkweed's greenish-yellow, urn-shaped flowers

Savannah milkweed

With its diminutive stature and greenish-yellow flowers, Savannah milkweed (Asclepias pedicellata) is oft overlooked in its native pineland and prairie habitats. It blooms late spring through fall, peaking in summer.
Read more… Savannah milkweed
Green antelopehorn in flower.

Green antelopehorn

Green antelopehorn (Asclepias viridis) is an herbaceous perennial wildflower found in pinelands, pine rocklands and disturbed areas in a few Florida counties. It flowers winter through summer, with peak blooms in spring.
Read more… Green antelopehorn
Whorled milkweed in flower.

Whorled milkweed

Whorled milkweed (Asclepias verticillata ) is one of the smaller, more delicate native milkweeds and is easily overlooked when not in bloom. It flowers late spring through summer and into early fall.
Read more… Whorled milkweed


Butterfly milkweed (Asclepias tuberosa) is a perennial that produces large, showy clusters of bright orange to reddish flowers from spring through fall. It occurs naturally in sandhills, pine flatwoods, and other sandy uplands.
Read more… Butterflyweed