Welsh’s Milkweed
Asclepias welshii N.H. Holmgren & P.K. Holmgren
A federally threatened dune endemic known from only a handful of active sand dune systems on the Utah–Arizona border, including the Coral Pink Sand Dunes. Thick woolly gray leaves and creamy flower clusters on plants that survive by growing up through shifting sand.
- Height
- 1.5 ft–4 ft
- Spread
- 2 ft–5 ft
- Flowers
- cream, pink
- Bloom
- May to July
- Light
- Full sun
- Soil moisture
- Dry
- USDA zones
- 5–8
- Leaves
- Opposite, ovate
- Sap
- Milky latex
- Roots
- Rhizomatous, spreads by root
- Stratification
- 60 days cold-moist
- Range
- 2 states
When it flowers
Welsh’s Milkweed blooms May to July, peaking in June.
How to identify it
- Broad, thick, densely white-woolly leaves in well-spaced opposite pairs.
- Creamy-white flowers tinged pink, in dense terminal clusters.
- Grows only in active, shifting sand dunes, so habitat alone identifies it.
Ecology and wildlife value
A dune specialist whose rhizomes let it re-emerge after burial by moving sand. Off-road vehicle traffic and dune stabilisation by invasive plants are the principal threats.
Growing welsh’s milkweed
Legally protected. Do not collect seed, plants or cuttings, and do not attempt to cultivate it from wild material.
Seed needs about 60 days of cold-moist stratification. Rhizomatous, spreads by root. See how to plant milkweed seed for the full method.
Cautions
Listed as Threatened under the US Endangered Species Act. Collection is prohibited. More on milkweed toxicity.
Where welsh’s milkweed grows
Recorded in 2 states: Arizona, Utah.
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 21339-2. Royal Botanic Gardens, Kew. Accepted name, authorship and global distribution.
- GBIF 3170262. Global Biodiversity Information Facility. Aggregated occurrence records.
- iNaturalist 158765. 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). Welsh’s Milkweed (Asclepias welshii). Retrieved DATE, from https://milkweedusa.com/species/welshs-milkweed/
"Welsh’s Milkweed (Asclepias welshii)." Milkweed USA, 2026, https://milkweedusa.com/species/welshs-milkweed/. Accessed DATE.
Milkweed USA. "Welsh’s Milkweed (Asclepias welshii)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/species/welshs-milkweed/.
@misc{milkweedusa_specieswelshsmilkweed,
title = {Welsh’s Milkweed (Asclepias welshii)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/species/welshs-milkweed/},
note = {Accessed DATE}
}