Engelmann’s Milkweed
Asclepias engelmanniana Woodson
A tall, sparse, almost skeletal prairie milkweed with long drooping linear leaves and small greenish-yellow flowers. It looks fragile and is anything but, with a taproot that goes deep into sandy plains soil.
- Height
- 2 ft–5 ft
- Spread
- 1 ft–2 ft
- Flowers
- green, yellow
- Bloom
- June to August
- Light
- Full sun
- Soil moisture
- Dry
- USDA zones
- 4–8
- Leaves
- Alternate, narrow
- Sap
- Milky latex
- Roots
- Deep taproot, resents transplanting
- Stratification
- 30 days cold-moist
- Range
- 8 states
When it flowers
Engelmann’s Milkweed blooms June to August, peaking in July.
How to identify it
- Very long, narrow, drooping alternate leaves on a tall slender stem.
- Small greenish-yellow flowers in loose clusters from the upper leaf axils.
- Distinctly gaunt outline compared with other plains milkweeds.
Ecology and wildlife value
A sandhills and shortgrass species used by monarchs during the fall migration through the central flyway.
Growing engelmann’s milkweed
Rarely cultivated. Needs deep sand and full exposure.
Seed needs about 30 days of cold-moist stratification. Deep taproot, resents transplanting. See how to plant milkweed seed for the full method.
Cautions
Standard narrow-leaf milkweed toxicity. More on milkweed toxicity.
Where engelmann’s milkweed grows
Recorded in 8 states: Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, Wyoming.
Distribution is generalized to state level. For county-level maps see USDA PLANTS and BONAP.
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 290400-2. Royal Botanic Gardens, Kew. Accepted name, authorship and global distribution.
- GBIF 3170267. Global Biodiversity Information Facility. Aggregated occurrence records.
- iNaturalist 158738. Community observations, photographs and phenology.
- Wikipedia. General-audience article on this species.
- 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). Engelmann’s Milkweed (Asclepias engelmanniana). Retrieved DATE, from https://milkweedusa.com/species/engelmanns-milkweed/
"Engelmann’s Milkweed (Asclepias engelmanniana)." Milkweed USA, 2026, https://milkweedusa.com/species/engelmanns-milkweed/. Accessed DATE.
Milkweed USA. "Engelmann’s Milkweed (Asclepias engelmanniana)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/species/engelmanns-milkweed/.
@misc{milkweedusa_speciesengelmannsmilkweed,
title = {Engelmann’s Milkweed (Asclepias engelmanniana)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/species/engelmanns-milkweed/},
note = {Accessed DATE}
}