| Family | Scientific Name | Common Name | Habitat | Distribution | Image |
|---|---|---|---|---|---|
| Apocynaceae | Asclepias incarnata ssp. incarnata | Western Swamp Milkweed | Swamps, marshes, especially over calcareous substrates, such as limestone or calcareous shale. | ME and s. QC west to MB, south to VA, s. TN (Chester, Wofford, & Kral 1997), AR, TX, and CO; disjunct in TX, NM, and UT. |  |
| Apocynaceae | Asclepias incarnata ssp. pulchra | Eastern Swamp Milkweed | Marshes, bogs, swamps. | NS and ME south to e. NC, w. SC, GA, and e. TN (Chester, Wofford, & Kral 1997), and s. FL. |  |