What is the participle or participial phrase in this sentence the violet kept on a sunny windowsill bloomed all summer?

In the sentence "The violet kept on a sunny Windowsill bloomed all summer," the participial phrase is "kept on a sunny Windowsill." However, it is worth noting that "bloomed" is the main verb, while "kept" serves as a past participle in this context, describing the subject "the violet." The phrase as a whole provides additional information about the violet's condition.