Angiosperms: Dicotyledons

Asclepiadaceae
Milkweed Family

• Notes: Asclepias sullivantii is very similar to A. syriaca except it is generally less robust, with smooth stems, leaves, and fruits. The leaves are narrower and opposite, 6” by 2”, and with slightly chordate bases and rounded tips with tiny points. The upper leaves are held more erect. There are fewer flowers per umbel. The fruits are about the same size, but they are smooth rather than hairy. Flowering begins in late June and continues until early August. Fruiting begins in late July. Seeds are shed in mid-September. A. sullivantii is restricted to low to mesic prairies. Prairie milkweed is uncommon on prairies, but perhaps it is often overlooked because of its close resemblance to A. syriaca.
• Bibliography from Biodiversity Heritage Library
• Vascular Plants of Iowa