Asclepias syriaca, also known as Common Milkweed, is a perennial wildflower native to North America. It typically grows to be about 3-4 feet tall. The flowers of Asclepias syriaca are pink to purple in color and have clusters of small, pink to purple, star-shaped flowers that are arranged in a round, umbel-like inflorescence. The flowers have five reflexed petals and a central crown of small, tubular flowers that are usually a pale yellow or green color. The inflorescence can be up to 4 inches (10 cm) across and is typically situated at the top of the stem. The flowers bloom from mid to late summer, and they can last for several weeks. After the flowers fade, they are followed by the characteristic seed pods, which are long, green, and narrow.
One unique feature of Asclepias syriaca is that it is a host plant for the Monarch butterfly. The leaves of the plant are the primary food source for Monarch caterpillars, and the plant is an important nectar source for adult butterflies. In addition, the plant is a popular food source for many other species of butterflies and moths.
Common Milkweed is a hardy plant and can grow in a variety of soil conditions including sandy, loamy, and clay soils. It is tolerant of drought conditions once established. It can tolerate some shade, but it will produce more flowers in full sun.