Milkweed

The milkweed filaments from the follicles are hollow and coated with wax, and have good insulation qualities. Tests have shown them to be superior to down feathers for insulation. During World War II, over 5,000 t (5,500 short tons) of milkweed floss was collected in the United States as a substitute for kapok. As of 2007, milkweed is grown commercially as a hypoallergenic filling for pillows.

Milkweed is beneficial to nearby plants, repelling some pests, especially wireworms.

Milkweed sap is also externally used as a natural remedy for poison ivy.

Being the sole food source of monarch butterfly larvae, the plant is often used in butterfly gardening.