During WWII the silky part attached to the seeds was used for life jackets.234 Milkweed is more buoyant then cork by 5 or 6 fold.234
Common milkweed, silkweed
2 Native Plant Society of Texas
4 “Your Country’s Armed Services Need Milkweed Floss: How You Can Help” :https://archive.org/stream/YourCountrysArmedServicesNeedMilkweedFlossHowYouCanHelp/YourCountrysArmedServicesNeedMilkweedFlossHowYouCanHelp_djvu.txt