Dandelions are much more than a weed; they are also valuable medicine.
Here are a list of things dandelions have been used to remedy
Insomnia (so long as tea made from roots or leaves is consumed at least six hours before bed; otherwise its diuretic properties will keep you up aka having to pee all night!)
Low Blood Pressure
Every part of the dandelion is edible, including its roots, leaves and blossoms. Young leaves are excellent in a tossed salad or cooked as greens. Dried leaves can be used for tea and roasted roots make a wonderful, healthful coffee substitute. Just be sure to harvest dandelions from a chemical free patch of land or you can purchase dandelion products (and get valuable advice) from your local health food store.
You can read an interesting testimony and a bit more about this incredible herb at Hardy Herbs.