The term poison milkweed refers to the plant species Asclepias syriaca. While this plant is commonly known as poison milkweed, there are several other terms that can be used to refer to it. These include common milkweed, silkweed, cottonweed, and Virginia silkweed. All of these terms refer to the same plant species, which is known for producing a toxic sap that can cause digestive issues and skin irritation. Despite its poisonous nature, this plant is still widely cultivated for its ornamental value and its importance as a food source for pollinators like monarch butterflies.