Curtiss’ milkweed

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

Curtiss’ milkweed (Asclepias curtissii) is a long-lived and somewhat mysterious milkweed endemic to the Florida scrub. The populations of this state-endangered wildflower are widely scattered and sometimes only a single plant will be found within a site. Its population dynamics have been challenging to study because it is very difficult to find when not in bloom and it can remain dormant through more than one season.

Curtiss’ milkweed is deciduous. Its woody stem can grow up to 4 feet long and typically leans, giving it an almost vine-like sprawl. Its leaves are dark green, oval, undulate and oppositely arranged. Flower umbels are born in the axils of the leaves and typically bloom in summer. Individual flowers have light green to tan reflexed corollas and a white upright corona with a light pink to purple tip.

Photo by Emily Bell
Photo by Emily Bell

Like all members of the Asclepias genus, Curtiss’ milkweed is a larval host plant for Monarch, Queen and Soldier butterflies. However, the levels of poisonous cardenolides that the caterpillars are adapted to feed on but typically deter other browsers are low in Curtiss’ milkweed and therefore it is sometimes foraged by deer. Learn more about Monarchs and Milkweed in Florida here.

Family: Apocynaceae (Dogbane family)
Native range: Peninsular Florida
To see where natural populations of Curtiss’ milkweed have been vouchered, visit
Lifespan: Perennial
Soil: Deep, extremely well-drained sand
Exposure: Full sun
Growth habit: Up to 4 feet, often leaning

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

For more 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

Longleaf milkweed

Longleaf milkweed (Asclepias longifolia ) 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.
Read more… Longleaf milkweed
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