A member of the sunflower family, the dandelion species is called Taraxacum officinale and is one of the most easily recognized weeds in the United States. The name dandelion means "tooth of the lion" and refers to the characteristic deeply indented leaves at the base of the plant. Each of these hardy plants is actually a cluster of small flowers. After blooming, the yellow petals are replaced with a series of stems with fluffy white threads.
A dandelion flower is surrounded by a series of yellow petals called bracts. There is an inner and outer layer of bracts. The inner bracts remain erect until the dandelion seeds mature at which point they turn downward, thereby permitting the seeds to disperse. The outer bracts always remain pointing in a downward direction.
The dandelion plant does not require pollination in order to reproduce; rather it self-pollinates and reproduces asexually through seeds by a method in botany called apomixis. It is the dandelion's process of reproducing which creates its characteristic fluffy white sphere.
Following self-pollination and flowering, the dandelion develops a round cluster of seed cases, or achenes. Each achene produces a seed. When mature, the inner layer of bracts points downward and the dandelion flower dries out for several days, eventually falling off, revealing a ball.
Fluffy White Sphere
The ball that remains once the flower falls off ultimately opens into a full sphere of as many as 200 thin fluffy white threads attached to a stem. This change can happen overnight.
The white tuft at the top of each stem acts as a parachute enabling the seed to travel on the breeze or be picked up when brushed by a passing animal or person, thereby reproducing the dandelion. It is this distinct fluffy sphere of the dandelion which enables it to reproduce.