Seeds from this Asclepias pumila or Plains Milkweed is one of the smallest milkweeds. Their leaves usually alternate in a tight spiral up the stems. These blossom in zones 4 to 8 throughout July and August and will bring more butterflies than you can imagine. The gorgous rosy gray colored blossoms are and dainty. These plants are perennials and grow in full sun and sandy dry soil is best for them. Quite a drought tolerant plant.