Curtiss’ Milkweed
Asclepias curtissii A. Gray
A Florida scrub endemic listed as endangered by the state, with wavy-edged pale leaves and greenish-white flowers, restricted to the ancient sand ridges of the peninsula.
Also called Curtiss’ Sandhill Milkweed.
- Height
- 1 ft–3 ft
- Spread
- 10 in–1.7 ft
- Flowers
- white, green
- Bloom
- April to September
- Light
- Full sun, Part shade
- Soil moisture
- Dry
- USDA zones
- 8–10
- Leaves
- Opposite, ovate
- Sap
- Milky latex
- Roots
- Deep taproot, resents transplanting
- Stratification
- None needed
- Range
- 1 state
When it flowers
Curtiss’ Milkweed blooms April to September, peaking in May and June.
How to identify it
- Wavy-margined, pale gray-green leaves in widely spaced pairs.
- Greenish-white flowers in open terminal clusters.
- Only in Florida scrub and sandhill on relict dune ridges.
Ecology and wildlife value
Confined to Florida scrub, one of the most threatened habitats in North America, most of which has been converted to citrus and housing.
Growing curtiss’ milkweed
State-listed as endangered in Florida. Do not collect from the wild; buy only nursery-propagated stock.
Seed needs no cold stratification and can be sown fresh. Deep taproot, resents transplanting. See how to plant milkweed seed for the full method.
Cautions
Endangered in Florida; collection from the wild is prohibited. More on milkweed toxicity.
Where curtiss’ milkweed grows
Recorded in 1 state: Florida.
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 94214-1. Royal Botanic Gardens, Kew. Accepted name, authorship and global distribution.
- GBIF 3170342. Global Biodiversity Information Facility. Aggregated occurrence records.
- iNaturalist 146969. 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). Curtiss’ Milkweed (Asclepias curtissii). Retrieved DATE, from https://milkweedusa.com/species/curtiss-milkweed/
"Curtiss’ Milkweed (Asclepias curtissii)." Milkweed USA, 2026, https://milkweedusa.com/species/curtiss-milkweed/. Accessed DATE.
Milkweed USA. "Curtiss’ Milkweed (Asclepias curtissii)." Last modified 2026-08-01. Accessed DATE. https://milkweedusa.com/species/curtiss-milkweed/.
@misc{milkweedusa_speciescurtissmilkweed,
title = {Curtiss’ Milkweed (Asclepias curtissii)},
author = {{Milkweed USA}},
year = {2026},
url = {https://milkweedusa.com/species/curtiss-milkweed/},
note = {Accessed DATE}
}