Nature's Oxymoron?

Each flower head is actually composed of thousands of small ray flowers. Each yellow petal-like structure is a different flower which eventually turns into a large gossamer seed ball. Many parts of the plant can be eaten, made into a drink such as coffee or wine, or used as a medicine. Unfortunately, some people are allergic to the plant and in numerous places it is so prolific that it is seriously interferring with agriculture. As a result, its beauty can be antithetical to its benefit.