• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Texas A&M Forest Service
  • Texas A&M Veterinary Medical Diagnostics Laboratory
  • Texas A&M AgriLife Extension Service
  • Texas A&M AgriLife Research
  • Texas A&M College of Agrculture and Life Sciences
AquaPlant
AquaPlantA Diagnostics Tool for Pond Plants and Algae
  • Menu
  • Home
  • Identify a Plant
  • Do I need a permit?
  • FAQs
  • Glossary
  • Videos
  • Online Courses
  • Get Help

Swamp Milkweed

Asclepias incarnata

Swamp Milkweed Locations in North America
Swamp Milkweed Locations in Southeast US

Swamp milkweed

Swamp milkweed

USDA, NRCS. 2018. The PLANTS Database (http://plants.usda.gov, 28 March 2018). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Illustration: USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner’s Sons, New York. Vol. 3: 26.

What is Swamp Milkweed?

Other common spellings and names include: pink milkweed.

Physical Characteristics

Leaves:

  • Opposite
  • Egg or sword-shaped
  • 2-5 inches long
  • Up to 1.5 inches wide
  • Leaf stalks up to 0.39 inches long

Flowers:

  • Usually paired at nodes
  • Many flowered
  • Small
  • Bright pink, rarely white in color

Fruit:

  • Dry
  • Opens on one side to release seed when ripe
  • Spindle-shaped
  • 2.75-3.5 inches long
  • Up to 0.5 inch thick
  • Smooth

Seeds:

  • Oval-shaped
  • 0.28-0.39 inches long

Stem:

  • Sturdy
  • 1.25-5 feet tall
  • Branching

Roots:

  • Short rootstalks

Where Does it Grow?

Swamp milkweed is an obligate wetland plant for the Gulf Coastal prairie and midwest regions and a facultative plant for the Great Plains region. Swamp milkweed can be found in marshes and long the edges of lakes and streams.

Bloom Color: Pink , Purple 
Bloom Time: Jun , Jul , Aug , Sep , Oct 

Pros and Cons of Swamp Milkweed

Milkweed is the only plant eaten by Monarch butterfly caterpillars, one of the reasons their numbers are dropping is the loss of space for milkweed to grow due to mowing or pesticides.

Flowers are beneficial to native bees.

Submerged portions of all aquatic plants provide habitats for many micro and macro invertebrates. These invertebrates in turn are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc.). After aquatic plants die, their decomposition by bacteria and fungi provides food (called “detritus”) for many aquatic invertebrates.

How to Manage This Plant
Plant Glossary

2023 Aquatic Webinars

Apr. 18: Pond Stocking 

May 16: Aquatic Plant ID & Management Options

Jun 20: Fish Management Strategies

Email Subscription

Receive updates on upcoming webinars and newly published materials.

Sign Up Now

Search for a type of plant

Hire a Professional Contact Your Ag & Natural Resource Agent Aquatic Plant Nurseries Permissions and Citations Aquatic Herbicide Tables
Aquatic Vegetation ID Cards
Texas A&M AgriLife Extension Service
Texas A&M University System Member

Photo Credits: The majority of the aquatic plant line drawings are the copyright of the University of Florida Center for Aquatic Plants (Gainsville). They are used with permission.

Aquatic plant photographs were provided by David Bayne, Jim Davis, Kelly Duffie, Billy Higginbotham, Michael Masser, John Clayton, Chetta Owens, Diane Smith, Joe Snow, Don Steinbach, Bridget Robinson Lassiter and Peter Woods.

You may use these photos, so long as you give credit to AquaPlant.

  • Compact with Texans
  • Privacy and Security
  • Accessibility Policy
  • State Link Policy
  • Statewide Search
  • Veterans Benefits
  • Military Families
  • Risk, Fraud & Misconduct Hotline
  • Texas Homeland Security
  • Texas Veterans Portal
  • Equal Opportunity
  • Open Records/Public Information