Pleasant Puzzle

Spring has sprung. And with that alliterative beginning I shall explain my pleasant puzzle. The following are the thoughts and narrative of one Kristin (or Kristin One if you should prefer) of a Tuesday morning early:

"What's this?"
I walked into my British Lit class at 7:55 am on Tuesday morning and noticed a small sprig of fresh white flowers of unknown classification laying conspicuously on a long stretch of black tabletop- more specifically, my section of black tabletop.
"Curious. Where on earth did they come from? And who put them there? Are they supposed to be for me, or did someone just leave them there randomly? Maybe someone forgot them. No, that's silly; this is the first class of the morning, the doors are locked before this class, and they aren't wilted so they must be new."
These thoughts rushed through my head almost all at once.
"Who would have known that I sit here? No one, except the people in this class."
I looked around to see if there were any likely suspects. None.
"They must not be specifically for me. But who would have left flowers on anyone's desk? That's something that Caitlin would do, but it couldn't have been her."
I began to set my backpack down and remove my books. Meanwhile, one of my fellow temporarily recurrent tabletop users came in to sit down at her usual seat, two seats away from me. She looked at the flowers and then smiled at me.
"Oh dear. She probably thinks that someone left them here for me as a gift. Oh well. I suppose she may think what she likes. But who on earth put them here? And why?"
Such was the puzzling scene I was met with early this morning, and it remains unsolved. I suppose I won't figure it out either, and so I have given it up as a pleasant puzzle with key pieces in absentia.