Here's why:

* Spores are used for reproduction in non-flowering plants (like ferns, mosses, and fungi). They are single-celled structures that can develop into a new plant.

* Flowers are the reproductive structures of flowering plants (angiosperms). They contain the ovary, which produces seeds (containing embryos) for reproduction.

In summary: Spores are a method of reproduction for certain plants, while flowers are the reproductive structures of flowering plants. They are distinct and different.