Milkweed Seeds
Today the vast majority of plant species are seed plants, or plants that produce seeds. I have often read or heard people talk about plants as being stationary. This is true of most mature seed plants, but untrue of the early stage of seed plants. The seed is the embryonic plant encased in protective tissue, allowing the embryo to survive desiccation. And, many seeds are adapted for travel -- they are mobile. Many seed plants can and will disperse great distances. Seeds are mainly dispersed by animals but some are dispersed by wind and others by water. The form and structure of the seed will give clues to the dispersal agent. Milkweed seeds possess a coma, which is comprised of long, white, silky strands of cellulose called floss. As the floss dries the coma opens up creating buoyancy, allowing seeds to drift on air currents (plant: butterfly milkweed "Asclepias tuberosa", family Apocynaceae).