Ooh! An inventory of herbs in the making! I do like mundane-seeming items like this, which come in surprisingly useful to the player who notices them. It all adds depth to the campaign world... Go to Comment
Let us hope the process of consuming and digestion cancels the herbs magical effects...
Actually, special research (or a miscast spell) may discover how to trigger this effect, if you ate the herb before. This may (in extreme) cause freezing of your whole body, or, somewhat more innocent, let you feel cold and perhaps make it easier to get the flu, or other disease.
Hmmm... weakening someone's immunity with a common, non-poisonous herb... quite devious. It is no good news for a kingdom to have a single sickly heir, and the king being too old to get a new one... Go to Comment
Maybe a local special effect causes this magic, a magical snow-storm or something? It does not have to be cold weather, it could be just the opposite (it's hot = flowers need to cool down lest they wilt...) or any regular magical effect. If it could be re-created, these flowers could be grown elsewhere.
Plot hook: research the phenomenon, and duplicate it for a wealthy merchant, an enterprising druid, or anyone with a taste for ice-cream. Go to Comment