There are a handful of U.S. States which have listed Milkweed species (Asclepias) in some form. There are also federally-listed Milkweed species which applies to many states. Johnny Butterflyseed has gathered some answers for you.
Quick Answer
Any U.S. state with native prairieland will likely have endangered Milkweed, due to habitat destruction.
Federally-Listed Milkweed
Applies from one to many or all states in the U.S.
Asclepias meadii Mead’s milkweed “Threatened Wherever found”
Asclepias prostrata Prostrate milkweed “Endangered Entire”
Asclepias welshii Welsh’s milkweed “Threatened Wherever found”
From https://ecos.fws.gov/ecp0/reports/ad-hoc-species-report?kingdom=P&status=E&status=T&status=EmE&status=EmT&status=EXPE&status=EXPN&status=SAE&status=SAT&mapstatus=3&fcrithab=on&fstatus=on&fspecrule=on&finvpop=on&fgroup=on&ffamily=on&header=Listed+Plants
Florida
Asclepias curtissii CURTISS’ MILKWEED
Asclepias viridiflora GREEN MILKWEED
Asclepias viridula SOUTHERN MILKWEED
From https://florida.plantatlas.usf.edu/
20 Florida-Native Sandhill Milkweed Seeds Ascslepias Humistrata Pinewood Milkweed
With Johnny Butterflyseed’s Sandhill Milkweed seeds, you’re not just planting flowers; you’re cultivating a living mosaic of nature’s marvels. Florida Native.
Illinois
Asclepias lanuginosa Wooly Milkweed
Asclepias meadii* Mead’s Milkweed
Asclepias ovalifolia Oval Milkweed
Asclepias stenophylla Narrow-leaved Green Milkweed
From https://www2.illinois.gov/sites/naturalheritage/Documents/IllinoisEndangeredandThreatenedSpecies.pdf
Indiana
Asclepias viridis green milkweed
Asclepias meadii Mead’s Milkweed
From https://www.in.gov/dnr/nature-preserves/files/np-Indiana-County-Endangered-Threatened-Rare-Species-List.pdf
Iowa
Asclepias meadii* Mead’s Milkweed
Eared milkweed Asclepias engelmanniana
From https://www.iowadnr.gov/Conservation/Iowas-Wildlife/Threatened-and-Endangered
Kansas
Asclepias meadii* Mead’s Milkweed
250 Butterfly Milkweed Seeds (Ascslepias Tuberosa) for North America
More than one full gram of Butterfly Milkweed Seeds (Asclepias tuberosa). Attracts Monarchs. Origin Kentucky. USDA Zones 3-8.
Texas
Asclepias prostrata Prostrate Milkweed
From https://tpwd.texas.gov/landwater/land/tcap/sgcn.phtml
Wisconsin
Asclepias meadii* Mead’s Milkweed
Purple Milkweed Asclepias purpurascens
From https://p.widencdn.net/byxof6/ER001
These are just a few examples, and the status of endangered Milkweed species can vary across states and change over time. It’s important to consult up-to-date sources or contact relevant conservation agencies for the most current and comprehensive information on endangered milkweed species in specific states.
Remember, if you don’t see Milkweed, you won’t see Milkweed Butterflies like the Monarch. Start your Monarch Waystation right away, and together we can help save Milkweed Butterflies… one day at a time!
20 Florida-Native Sandhill Milkweed Seeds Ascslepias Humistrata Pinewood Milkweed
With Johnny Butterflyseed’s Sandhill Milkweed seeds, you’re not just planting flowers; you’re cultivating a living mosaic of nature’s marvels. Florida Native.