Butterfly Weed
Asclepias tuberosa
Photo Citations
Naturedigger provided all images of butterfly weed for this slide.
Asclepias tuberosa Profile
Common Name(s):
butterfly weed
butterfly milkweed
common butterfly-weed
orange milkweed
pleurisy root
chigger flower
chieger flower
Indian paintbrush
Scientific Name:
Asclepias tuberosa
Native Range:
United States: AL, AR, AZ, CA, CO, CT, DC, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS,
NC, NE, NH, NJ, NM, NY, OH, OK, PA, RI, SC, SD, TN, TX, UT, VA, VT, WI, WV
CANADA: NB, NL, NS, ON, QC
USDA Symbol:
ASTU
Habitat:
• dry, rocky or sandy soils
• open woods
• canyons
• glades
• prairies
• fields
• roadsides
Growing Conditions:
• full sun
• poor, dry soils
Plant Height:
• 1-3 feet (30-60 centimeters)
Stem Description:
• hairy
• erect
• light green to dull reddish purple
• mature plants have multiple stems
Leaf Description:
• narrow, stiff, lance-shaped
• 2.5-3.5 inches long (5-9 centimeters) and 0.5-0.75 inches (1-2 centimeters) wide
• tips are acute
• leaf base is cordate, truncate or rounded
• leaves are sessile or have very short petioles
• upper leaf surface deeper green than underside
Leaf Arrangement:
• alternate
Leaf Margin:
• entire
Leaf Surface:
• glabrous, may be short pubescent
Flowering Period:
• May through September
Flower Description:
• hoods are approximately 0.25 inches (6 millimeters) long and horns are slightly smaller around 0.15 inches (3 millimeters)
• horns protrude through the hoods and are sickle-shaped
• corolla (petals) reflexes backwards
• large flat-topped or slightly domed clusters at the top of the stem
• umbels are 1.5 to 2.0 inches (4-5 centimeters) across
• 8-25 flowers per umbel
Flower Color:
• corolla, hoods and horns are bright orange to yellow-orange, rarely red and only yellow if growing in the west
Pod Description:
• narrow; grayish green; covered with short hairs
• 3-6 inches (1.5-3 centimeters) long
Seed Description:
0.15 inches (0.4 centimeters) long and 0.5-0.75 inches (1.25-2.0 centimeters) across
Other Information:
• used to treat lung conditions, which is how it got the common name pleurisy root
• unlike other milkweed species, butterfly weed oozes a clear watery sap as opposed to a white, milky sap
• similar in appearance to Asclepias lanceolata, but has a larger number of flowers
• this species has long-lasting blooms and may bloom twice during the season
• the species name tuberosa, refers to the tuberous (knobby tube-like swollen) root of butterfly weed
To Locate and Purchase Seeds (when available):
Xerces Society Milkweed Seed Finder
Milkweed and Wildflower Vendors
For More Information About This Species Visit:
Lady Bird Johnson Wildflower Center
Xerces Regional Milkweed Guide