Butterfly Milk Weed Balloon Plant, Hairy Balls Seeds,Asclepias Physoca Free Shipping. 24+ Seeds. A slender, deciduous shrub, often treated as an annual. Quick and easy to grow, producing stems of small white flowers that magically transform into unusual translucent , soft, spiny balloons. Adds fun to borders and cut flower arrangements. As part of the Milkweed family, these are also host plants for the Monarch butterfly caterpillar.