What a wonderful adaptation! What excellent design! How fun it is to blow the seeds off the head!
Dandelion is Taraxacum officinale, or one of its close relatives. T. officinale was originally imported from Europe, and has now spread widely through North America, where some of the native Taraxacum species are now endangered.
It is a composite flower, meaning that the “flower” is actually a collection of many small true flowers, some of which bear the petals along the outside edge and most of which fill the yellow center. Each of the seeds is produced by one of the true flowers.
Rather than write lots about this well-known, completely edible, very common plant, which some people might think of as a weed, I refer you to the excellent Wikipedia page about dandelions and their many closely related relatives. Enjoy!