The best known of our flowers, it is present everywhere.
Often despised, sometime hated, yet it is very interesting: the leaves begin their developments under the ground, the flower opens and closes according to the available light, once mature the stem is parallel to the ground while the capitulum (flower head) turns 90 ° to the sky, then the stem straightens once the fruits (achene and pappus) are mature.
Although it is known as one species it is rather an aggregate of species, this polymorphism is largely due to the fact that ova can develop without fertilization.