“Flowering Phenology” describes the current set of available annotations, so it works for me in that regard. But it does kinda limit the category if we want to add other life stages in the future other than flowering stages. And as already mentioned, it would be really nice to at least have a category for “not flowering or fruiting” or something like that, to distinguish from lack of annotation = not evaluated yet.
And yes, terms like Flowers Budding, Flowers Open, Fruits Developing, would more precisely define the annotations as currently intended, I think.