Dandelions are common yellow flowers with many small pointed petals that many people classify as weeds. They are a very widespread flower. Though not native to the United States, they are now found in all 50 of them, as well as most other countries around the world. They spread quickly across any lawn if left unchecked. They can be difficult to eradicate in part because they have more than one method of reproducing themselves. This gives them multiple ways to spread.
Most people are familiar with the common method of dandelion reproduction. They form seeds that are attached to puffy white bits of fluff. These seeds and fluff give the flowers a white puffy appearance. When the seeds detach from the flower head, the wind catches the fluff and carries it away, sometimes over great distances. The seed is then able to begin life in a new location.
Different Methods of Pollination
Formation of a fertile seed requires both male and female reproductive organs, even in flowers. Insects carry pollen from the male reproductive organs to the female reproductive organs in order to accomplish the formation of a fertile seed. Dandelions have two different ways they can go about this. The insects may carry the pollen from one flower to another. However, dandelions have both male and female organs on the same flower. The flowers can pollinate themselves. Thus it only takes one dandelion to reproduce itself and spread over a lawn.
Reproduction from Buds
Dandelions are even capable of reproducing themselves when there isn't enough sunlight to cause the flower buds to open. In this case the male parts pollinate the female parts they are pressed up against. The resultant fertile seeds push their way out of the top of the bud.
This seed production is at its peak from early April to early June. It peaks again in the late fall. However, the seed production can happen almost all throughout the year. Each dandelion, when it goes to seed, produces between 125 and 300 seeds.
Reproduction from the Taproot
The dandelion also has another means of reproduction. They can regrow the whole plant from the taproot. this is why mowing them does no good at controlling them. Cutting off the stem above the ground leaves the taproot intact below the ground. Indeed, the dandelion does not even need a whole taproot to accomplish this trick. All it takes is a mere 2 millimeters of the root to germinate a whole new flower.