Dandelions are a species of flowering plant known by the scientific name Taraxacum officinale. Dandelions are bright and colorful plants that are known mainly for the seeds they produce. You can usually see kids blowing the air catching seeds in the wind. The plants can get pretty big in size, and have deep taproots. They grow in mostly open sunny fields or lawns. But you can sometimes find them in cracks and crannies.
The dandelion is a biennial or perennial herbaceous plant. The plant, when mature, rises from a deep taproot that has a milky substance if and when cut. Its leaves are often hairy, though sometimes are not; they have deep margins; and are all together at the base of the dandelion. The dandelion grows bright yellow flower heads that are 1 to 2 inches across, and have petal-like flowers. The seeds are enclosed on the fruiting bodies of the dandelion and are attached to a long, slender stem.
The dandelion reproduces asexually, so seed production usually happens without pollination. Seed production can range from 54 to 172 seeds per head and a single dandelion can produce more than 2000 seeds. Dandelion seeds are non-dormant when first produced. There have been some estimations that more than 240,000,000 seeds per acre are produced annually by dandelions. Dandelion seeds are easily scattered by the wind, since the pappus that are attached to the seeds expands and forms a parachute-like structure, and the wind carries them away. The flower head is usually surrounded by "bracts", the inside bracts stand straight up until the seeds are mature, then flex down to allow the seeds to spread. The outer bracts are always faced downward until mature.  Dandelions flower more in early summer with "late bloomers" in mid-September to early October. There are two different patterns of "flowering". In the early spring flower heads stay open from sunrise to dusk, but in June to July the flower heads close by noon.
The Dandelion was first found in Europe and Asia, and then spread throughout the whole world.  Dandelions can be well-adapted to "disturbed habitats", like lawns, and sunny open places. Dandelions can spread further than normal plants, but they are extremely hard to kill or exterminate. 
The word dandelion comes from the Old French language, it means "lion's tooth", describing the Dandelion's sharp-lobed leaves. The dandelion in Norwegian is called Lovetann, which means "lion's tooth". In German the dandelion is called Lowenzahn which also means "lions' tooth". In modern French the Dandelion is called pissenlit, which menas "urinate in bed"; describing it's fluid characteristics. "Piscialletto" is an Italian folkname, as well as "Pissabeds" being the English folk name for the Dandelion. In Spanish, it is called "meacamas", but also called "diente de leon". In Portuguese the common name for the Dandelion is "dente-de-leao" which also means "lion's tooth". The Dandelion is called "karahindiba" in Turkish meaning "black endive". There are 2 Hungarian names for the Dandelion, the first one is kutyatej, which means "dog milk" naming it after the white fluid that you find when you break the stem. And gyermeklancfu, which means "child's chain grass", naming it after children picking dandelions and making crowns out of them.
Despite many considering it a weed, the dandelion plant is used often in salads, and is even farmed for this purpose. The leaves can be eaten cooked or raw, and are high in Vitamins A and C as well as in iron. The plant is also used for its medicinal qualities. It is a recognized diuretic, and decoctions are given for anemia, jaundice, and nervousness. Furthermore, farmers find dandelions beneficial in loosening the soil.