# Prairie Milkweed (Asclepias sullivantii)

> Common milkweed’s refined cousin: the same big pink umbels and broad leaves, but smooth and hairless throughout, with an elegant red midrib and none of the coarseness. A tallgrass prairie plant that has declined sharply with the prairie itself.

Source: https://milkweedusa.com/species/prairie-milkweed/  
Licence: CC BY 4.0 (Milkweed USA)

## Summary

Common milkweed’s refined cousin: the same big pink umbels and broad leaves, but smooth and hairless throughout, with an elegant red midrib and none of the coarseness. A tallgrass prairie plant that has declined sharply with the prairie itself.

## Key facts

| Field | Value |
| --- | --- |
| Scientific name | Asclepias sullivantii Engelm. ex A. Gray |
| Genus | Asclepias |
| Family | Apocynaceae |
| Common names | Prairie Milkweed, Sullivant’s Milkweed, Smooth Milkweed |
| Status | Native |
| Height | 2 ft–4 ft |
| Spread | 1.5 ft–3 ft |
| Flower color | pink, rose |
| Bloom period | June to July |
| Light | Full sun |
| Soil moisture | Average, Wet |
| USDA zones | 3-7 |
| Leaf arrangement | opposite |
| Leaf shape | oblong |
| Sap | Milky latex |
| Root system | Rhizomatous, spreads by root |
| Seed stratification | 30 days cold-moist |
| Monarch value (0-5) | 5 |
| Garden value (0-5) | 4 |
| Nectar value (0-5) | 4 |
| US states recorded | Iowa, Illinois, Indiana, Kansas, Kentucky, Michigan, Minnesota, Missouri, North Dakota, Nebraska, Ohio, Oklahoma, South Dakota, Wisconsin |

## Identification

- Completely smooth and hairless, with no down on stems, leaves or pods.
- Leaf midrib is often flushed pink or red.
- Leaves have a small abrupt point at the tip and are held stiffly upright.
- Pods are smooth with only a few short blunt projections, unlike the warty pods of common milkweed.

## Ecology

A high-value monarch host with broad, soft leaves, now uncommon because it grows on exactly the deep moist prairie soils that were converted to row crops. Conservation-listed in several states.

## Growing

A far better garden plant than common milkweed: similar looks, much slower spread. Prefers heavier, moister soil. Seed and plants are increasingly available from prairie nurseries.

## Cautions

Standard milkweed cautions.

## Questions

**How is prairie milkweed different from common milkweed?**

Prairie milkweed is completely hairless, has a reddish leaf midrib and nearly smooth pods, and spreads far less aggressively. Common milkweed is downy throughout with warty, spiny pods.

## References

- Plants of the World Online: https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:94678-1
- GBIF: https://www.gbif.org/species/3170265
- iNaturalist: https://www.inaturalist.org/taxa/158761
- Wikipedia: https://en.wikipedia.org/wiki/Asclepias_sullivantii
- BONAP county map: https://bonap.net/MapGallery/County/Asclepias%20sullivantii.png
- NatureServe: https://explorer.natureserve.org/Search?searchTerm=Asclepias%20sullivantii

## Photographs

- Asclepias sullivantii (gmayfield10, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Asclepias_sullivantii.jpg
- Prairie Milkweed (Asclepias sullivantii) - 28366153785 (wackybadger, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Prairie_Milkweed_(Asclepias_sullivantii)_-_28366153785.jpg
- Prairie Milkweed (Asclepias sullivantii) - 28262579022 (wackybadger, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Prairie_Milkweed_(Asclepias_sullivantii)_-_28262579022.jpg
- Prairie Milkweed (Asclepias sullivantii) (wackybadger, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Prairie_Milkweed_(Asclepias_sullivantii).jpg
- Prairie Milkweed (Asclepias sullivantii) - 28287343981 (wackybadger, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Prairie_Milkweed_(Asclepias_sullivantii)_-_28287343981.jpg
- Prairie Milkweed (Asclepias sullivantii) - 28366208795 (wackybadger, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Prairie_Milkweed_(Asclepias_sullivantii)_-_28366208795.jpg
- Prairie Milkweed (Asclepias sullivantii) - 28262660652 (wackybadger, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Prairie_Milkweed_(Asclepias_sullivantii)_-_28262660652.jpg
- Prairie Milkweed (Asclepias sullivantii) - 28083645100 (wackybadger, CC BY-SA 2.0): https://commons.wikimedia.org/wiki/File:Prairie_Milkweed_(Asclepias_sullivantii)_-_28083645100.jpg

## How to cite

Milkweed USA. (2026). Prairie Milkweed (Asclepias sullivantii). https://milkweedusa.com/species/prairie-milkweed/