Heart-leaf Milkweed ( Asclepias cardifolia ) is a species of milkweed plant . It is also known as Purple Milkweed ( the species Asclepias purpurascens is also known as Purple Milkweed ) . Asclepias cordifolia is a species of milkweed commonly called Heart-leaf milkweed or Purple milkweed ( a common name shared with another milkweed , Asclepias purpurascens ) .