Cyndi and I were discussing cut flowers and the subject of re-cutting the stems before putting them in water came up. She commented that you should always re-cut them under water so they last longer. I know you should always re-cut them but I'd never heard the under water part before so I tried to confirm it.
All I could find was, more or less, many people all citing each other or "everyone knows this" kind of answers. Recognizing that "the plural of anecdote is not data", I wonder if there is any real science to support this.
I have no idea where to look for more information but this group of really smart people seemed like a good place to start.