Asclepias syriaca, commonly called common milkweed, butterfly flower, silkweed, silky swallow-wort, and Virginia silkweed, is a species of flowering plant. In addition to being beautiful, Milkweed is a very important plant because it is a host for the beloved MONARCH butterfly. Monarch larvae feed exclusively on Milkweeds. That means if there is no Milkweed, there would be no Monarchs :( It is also an important nectar plant for bees and other insects. The common name Milkweed was given to this plant because of its milky juice. The scientific name comes from Asclepius, the Greek god of healing, because of the many folk-medicinal uses for the milkweed plants. LIGHT REQUIREMENTS: Sun - Part Shade . . . SOIL / WATER: Average - Dry. BLOOM TIME: Summer. HARDINESS ZONE: 3 - 9.