Butterfly Weed, Canada Root, Chieger Flower, Chigger Flower, Fluxroot, Indian Paintbrush, Indian Posy, Orange Milkweed, Orange Root, Orange Swallow-Wort, Pleurisy Root, Silky Swallow-Wort, Tuber Root, Yellow Milkweed, White-Root, Windroot, Butterfly Love, Butterfly Milkweed

Asclepias tuberosa

(Asclepias tuberosa subsp. interior)

ass-KLE-pee-us  too-ber-OH-suh

Synonyms of Asclepias tuberosa subsp. interior Woodson (2) (Updated on 11-17-23 from Plants of the World Online): Asclepias tuberosa var. interior (Woodson) Shinners, Asclepias tuberosa subsp. terminalis Woodson

Asclepias tuberosa L. is the accepted scientific name for the Butterfly Weed. The genus and species were named and described by Carl von Linnaeus in the first volume of the first edition of Species Plantarum in 1753.

Accepted Infraspecific Names (3) (Updated on 11-12-22 from POWO): Asclepias tuberosa subsp. interior Woodson, Asclepias tuberosa subsp. rolfsii (Britton ex Vail) Woodson, *Asclepias tuberosa subsp. tuberosa (autonym). *When an infraspecific taxon is named, an autonym (“type-specimen”) is automatically generated whose description is closest to the (original) species. All have their own list of synonyms… Plants found in Missouri are Asclepias tuberosa subsp. interior.

As of 11-17-23 when this page was last updated, Plants of the World Online by Kew lists 204 species in the Asclepias genus. It is a member of the plant family Apocynaceae with 376 genera. Those numbers could change as updates are made on POWO.

The above distribution map for Asclepias tuberosa is from Plants of the World Online. The map on the USDA Plants Database for North America is the same. The maps include the species and lower taxon. You can click on the links to find maps for the subspecies.

The map on iNaturalist shows where members have made observations. Anyone can join and it is a great website to confirm and share your observations. The maps on iNaturalist are continually updated as members post new observations.

THERE ARE SEVERAL LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING AND TO HELP WITH A BETTER POSITIVE ID.

I always like the bright reddish-orange flowers of the Butterfly Weed. There aren’t any growing on my farm and they really aren’t as common in my neck of the woods as other Milkweed. In 2013, I was surprised to see a small colony growing in a neighbor’s pasture in the back of the farm. Well, of course, I climbed over the fence. They are growing hit-and-miss in areas along a few highways I travel on but I had never stopped for photos.

Asclepias tuberosa is one of the most popular of the Milkweeds due to its bright orange, yellow-orange, and sometimes yellow flowers. Plants grow to around 2 1/2’ tall from fairly deep taproots. Plants found in Missouri are identified as Asclepias tuberosa subsp. interior. 

Asclepias tuberosa prefers growing in light shade to full sun in well-draining soil of various types. They are commonly seen in pastures, along backroads and highways, and are popular as cultivated plants. Plants can be grown from seed but it may take a few years before they flower. 

<<<<2018>>>>

I found a nice colony of Asclepias tuberosa growing along a back road south of town on July 1 in 2018. I was able to take several good photos…

Plants grow multiple stems and are sometimes branched toward the top. Young plants usually have a single stem. Stems are either light green or reddish purple with spreading hairs.

Plants contain both terminal (top of stem) and axillary umbels (clusters of flowers) that grow from the axils of upper leaves. The umbels (clusters of flowers) may be sessile or short-stalked. Umbels contain 6-25 flowers. 

Each flower has 5 sepals, 5 petals, and five horned hoods. I am not going to get into the complicated terminology without detailed close-ups… 🙂 

This is one of a few Asclepias species that grow leaves in an alternate manner rather than having opposite pairs along the stem. Leaves are said to be linear-oblong, lanceolate, to lanceolate-oblong in shape, 2 1/2-3 1/‘“ long x 1/2-3/4” across. The tips of the leaves are pointed (acute) while the base is rounded and sort of folds under (revolute). Leaves are toothless and either have short petioles (leaf stems) or may be sessile (no petioles). The upper leaf surface is medium to dark green, either smooth (glabrous) or have short hairs (pubescent).

The leaf undersides are lighter green with longer hair, especially along the veins. The leaves contain no latex sap.

<<<<2020>>>>

While working out of town in 2020, I had to stop at a vacant house that had a flower bed full of Asclepias tuberosa. Even though there were no flowers, I figured they were likely A. tuberosa or they wouldn’t likely be in a flower bed.

As you can see, the fruit are fairly long and smooth…

I took these photos and picked a few seed pods… Which I have not planted yet… Nor have I taken photos of this species since 2020. Well, maybe I could have if I panted the seed…

I found a good write-up called, “The Story of an Organism: Common Milkweed” by Craig Holdrege from The Nature Institute. You Can read it by clicking HERE… It’s quite a story that leaves nothing out about Milkweeds.

There are more photos at the bottom of the page…

I live on a small farm in Windsor, Missouri where I enjoy gardening, collecting plants, and identifying wildflowers. The farm is in Pettis County but Henry County is across the street, and Benton and Johnson aren’t far away. I have grown over 500 different plants and identified over 250 species of wildflowers (most have pages listed on the right side of the page). I am not an expert, botanist, or horticulturalist. I just like growing, photographing, and writing about my experience. I rely on several websites for ID and a few horticulturalists I contact if I cannot figure them out. Wildflowers can be somewhat variable from location to location, so sometimes it gets a bit confusing. If you see I have made an error, please let me know so I can correct what I have written.

I hope you found this page useful and be sure to check the links below for more information. They were written by experts and provide much more information. Some sites may not be up-to-date but they are always a work in progress. If you can, I would appreciate it if you would click on the “Like” below and leave a comment. It helps us bloggers stay motivated. You can also send an email to me at thebelmontrooster@yahoo.com. I would enjoy hearing from you especially if you notice something is a bit whacky.

FOR FURTHER READING:
PLANTS OF THE WORLD ONLINE (GENUS/SPECIES)
INTERNATIONAL PLANT NAMES INDEX (GENUS/SPECIES)
TROPICOS (GENUS/SPECIES)
WORLD FLORA ONLINE (GENUS/SPECIES)
WIKIPEDIA (GENUS/SPECIES)
USDA PLANTS DATABASE
USDA PLANT GUIDE
DAVE’S GARDEN
MISSOURI PLANTS
MISSOURI BOTANICAL GARDEN
MSU-MIDWEST WEEDS AND WILDFLOWERS
MISSOURI DEPARTMENT OF CONSERVATION
iNATURALIST
WILDFLOWER SEARCH
ILLINOIS WILDFLOWERS
MINNESOTA WILDFLOWERS
KANSAS WILDFLOWERS AND GRASSES
PFAF(PLANTS FOR A FUTURE)
GO BOTANY
LADY BIRD JOHNSON WILDFLOWER CENTER
FLORA FINDER
FRIENDS OF THE WILDFLOWER GARDEN
NORTH CAROLINA STATE UNIVERSITY
GARDENIA
MONARCH WATCH
U.S. FOREST SERVICE
MASTER GARDENERS OF NORTHERN VIRGINIA
UNIVERSITY OF WISCONSIN
U.S. WILDFLOWERS

NOTE: The data (figures, maps, accepted names, etc.) may not match on these websites. It depends on when and how they make updates and when their sources make updates. Some websites have hundreds and even many thousands of species to keep up with. Accepted scientific names change periodically and it can be hard to keep with as well. Some of the links may use a name that is a synonym on other sites. In my opinion, Plants of the World Online by Kew is the most reliable and up-to-date plant database and they make updates regularly. I make updates “at least” once a year and when I write new pages or add new photos but I do get behind. We are all a work in progress. 🙂

PHOTOS TAKEN IN 2023…