I admit I’m not overly fond of the “no evidence of flowering” annotation. Some of that is based on the way it messed with a series of projects I had set up to collect all observations with plant phenology annotations. These projects used to include just budding. flowering, and fruiting stages until “no evidence” came up. Based on previous forum threads about these annotations, I think “no evidence” was added so all plant observations could receive an annotation. By that logic, eventually all plants will end up in such projects.
Part of the value of these annotations I think is being able to search for observations that show reproductive structures that aid in identifications. The ability to limit to or exclude certain annotations is most easily accessed on the Identify page (doing it in Explore pretty much requires URL hacks). “No evidence of flowering” is mutually exclusive to the other three, meaning once it is on an observation it can no longer be annotated as budding, flowering, or fruiting. So nowadays I usually ask the question: Does this observation contain pictures showing flower/fruit parts? If yes, I try to give it an annotations that would make it pop up in a search for that.
This is somewhat different from using these annotations in their strict phenophase terms, as has been discussed before. As pointed out especially for the species in question that prompted this thread, there are some stages that do not fall into a stricter definition of budding, flowering, and fruiting. However, “no evidence” clearly would be wrong for these observations because they have pictures with persistent flower parts, e.g. calyx, seed pods, and this clearly shows evidence of flowering but at a phenology stage between the available choices. What to do with those? Do we need a fifth category? Budding, flowering, fruiting, other evidence, and no evidence?