Where did you get the seeds from? Were they from "bagseed?"
It appears that the plant with the seeds is what is commonly called a "hermaphrodite." It grew male parts (stamen) and those parts fertilized the pistils, which then formed calyxes that contain the seeds.
It's always best to check for male parts when in flowering, especially with bagseed and "feminized" seeds. You'll notice small pods that look like grapes, or they will look like small bananas; yellow, long and small.
You ALWAYS want to remove any plant that has turned hermie, to avoid pollenating your other plants, and creating more seeds.