Plains Milkweed
Asclepias pumila (A. Gray) Vail
A knee-high-at-most tuft of fine, almost dill-like foliage carrying tiny cream flowers, scattered across shortgrass prairie from Montana to the Texas Panhandle. Easily mistaken for a grass until it blooms.
Also called Low Milkweed, Dwarf Milkweed.
- Height
- 4 in–1 ft
- Spread
- 6 in–1.5 ft
- Flowers
- white, cream
- Bloom
- June to September
- Light
- Full sun
- Soil moisture
- Dry
- USDA zones
- 3–8
- Leaves
- Alternate, threadlike
- Sap
- Milky latex
- Roots
- Rhizomatous, spreads by root
- Stratification
- 30 days cold-moist
- Range
- 10 states
When it flowers
Plains Milkweed blooms June to September, peaking in July and August.
How to identify it
- Rarely over a foot tall, with crowded thread-fine alternate leaves.
- Small white to cream flower clusters at the stem tips.
- Grows in dense shortgrass and on hard-packed prairie soils where taller milkweeds cannot compete.
Unfamiliar words are in the glossary, and the identification key will narrow a plant down from what you can see.
Ecology and wildlife value
A genuine shortgrass-prairie specialist. Monarchs use it in the western Great Plains where larger species are absent, and it is important to small native bees on otherwise flowerless rangeland.
Monarchs are not the only thing that will find it. Expect large milkweed bugs on ripening pods, oleander aphids on the stems, red milkweed beetles at the flowers and, in late summer, milkweed tussock moths. Everything that lives on milkweed.
Growing plains milkweed
Very drought- and cold-hardy; suited to gravel gardens, green roofs and rock gardens. Spreads slowly by rhizome into a low patch.
Seed needs about 30 days of cold-moist stratification. Rhizomatous, spreads by root. See how to plant milkweed seed for the full method.
Cautions
Narrow-leaved and moderately toxic; a minor component of rangeland poisoning risk. More on milkweed toxicity.
Where plains milkweed grows
Recorded in 10 states: Colorado, Kansas, Montana, North Dakota, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, Wyoming.
County records from USDA PLANTS, public domain. Cross-check against BONAP and your regional flora before making management decisions.
References and further reading
Names, ranges and conservation status here are drawn from the databases below. Where those disagree with a regional flora, trust the flora.
- Plants of the World Online 21273-2. Royal Botanic Gardens, Kew. Accepted name, authorship and global distribution.
- GBIF 3170288. Global Biodiversity Information Facility. Aggregated occurrence records.
- iNaturalist 158756. Community observations, photographs and phenology.
- BONAP county distribution map. Biota of North America Program. County-level range map.
- NatureServe Explorer. Conservation status ranks at global and state level.
- World Flora Online. Nomenclature and synonymy.
- Woodson, R. E. (1954). The North American species of Asclepias L.. Annals of the Missouri Botanical Garden 41(1): 1–211. The monograph the modern taxonomy of the genus still rests on. View
- Flora of North America Editorial Committee (eds.) (2026). Flora of North America North of Mexico. Oxford University Press, New York and Oxford. Accepted names, keys and descriptions for the North American flora. View
- Royal Botanic Gardens, Kew (2026). Plants of the World Online. Facilitated by the Royal Botanic Gardens, Kew. Nomenclature and global distribution, keyed to IPNI name identifiers. View
- Kartesz, J. T. (Biota of North America Program) (2026). North American Plant Atlas. BONAP, Chapel Hill, North Carolina. County-level distribution maps, the basis for the ranges generalized here. View
- USDA, NRCS (2026). The PLANTS Database. National Plant Data Team, Greensboro, North Carolina. State-level distribution, wetland status and nomenclature. View
- Agrawal, A. A. (2017). Monarchs and Milkweed: A Migrating Butterfly, a Poisonous Plant, and Their Remarkable Story of Coevolution. Princeton University Press. The standard general account of the milkweed and monarch relationship. View
Cite this page
This page is licensed CC BY 4.0. Quote it, adapt it and reuse it, including commercially, as long as you credit Milkweed USA and link back.
Milkweed USA. (2026). Plains Milkweed (Asclepias pumila). Retrieved DATE, from https://milkweedusa.com/species/plains-milkweed/
"Plains Milkweed (Asclepias pumila)." Milkweed USA, 2026, https://milkweedusa.com/species/plains-milkweed/. Accessed DATE.
Milkweed USA. "Plains Milkweed (Asclepias pumila)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/species/plains-milkweed/.
@misc{milkweedusa_speciesplainsmilkweed,
title = {Plains Milkweed (Asclepias pumila)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/species/plains-milkweed/},
note = {Accessed DATE}
}