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Asclepias perennis (White swamp milkweed)
Cressler, Alan

Asclepias perennis

Asclepias perennis Walter

White Swamp Milkweed, Aquatic Milkweed

Asclepiadaceae (Milkweed Family)



USDA Native Status: L48 (N)

Stem is a dark purplish-green color in contrast to the evergreen color of the leaves. Stands erect to ascending. Leaf arrangement is opposite. Leaf attachment is petiolate with short petioles approximately 2/3 in (1 1/2 cm) long. 3+/- umbels to a stem (Webref 20).

This species can be easily identified before the flowers open because the tips of the corollas are pink creating a large pink spot at the apex of an unopened flower. Leaves are relatively short and narrow. Grows in areas with soils that are continuously wet (Webref 20).


From the Image Gallery

44 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Leaf Arrangement: Opposite
Leaf Shape: Elliptic , Linear
Leaf Pubescence: Glabrous
Leaf Margin: Entire
Inflorescence: Umbel
Fruit Type: Follicle
Size Notes: Up to about 32 inches tall.
Leaf: Green, linear to a narrow elliptic, 3-5 in (8-13 cm) long by 1/2-1 1/2 in (1-4 cm) wide. Leaf vein and underside are a duller green.
Flower: Glabrous. Umbels erect with 25 +/- flowers presented as a flat panicle. Tips of the corolla can sometimes be tinged with pink. Corollas, hoods, and horns are usually white or light pink. Horns protrude through the hoods. Corolla reflexes backward. Each flower is approximately 1/8-3/16 in (3-4 mm) long and 1/16 in (2 mm) wide.
Fruit: Follicles pendulous. Smooth, hairless, long 1 1/2 -2 1/2 in (4 - 6 cm) , and narrow 1/2 -1 in (1-2 1/2 cm) wide.

Bloom Information

Bloom Color: White , Pink
Bloom Time: May , Jun , Jul , Aug , Sep


USA: AL , AR , FL , GA , IL , IN , KY , LA , MO , MS , SC , TN , TX
Native Habitat: Hydrated soils, floodplains, water way margins, marshes, cypress swamps, ditches, and wet lands.

Growing Conditions

Light Requirement: Sun , Part Shade
Soil Moisture: Moist , Wet


Conspicuous Flowers: yes
Attracts: Butterflies

Value to Beneficial Insects

Special Value to Native Bees
Special Value to Bumble Bees
Special Value to Honey Bees
Supports Conservation Biological Control

This information was provided by the Pollinator Program at The Xerces Society for Invertebrate Conservation.


Propagation Material: Seeds

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

Web Reference

Webref 20 - Milkweed Profiles (0) Monarch Watch

Additional resources

USDA: Find Asclepias perennis in USDA Plants
FNA: Find Asclepias perennis in the Flora of North America (if available)
Google: Search Google for Asclepias perennis


Record Modified: 2022-09-19
Research By: TWC Staff

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