Curiosity got the better of me. I've been tending my husband's tiny tree since it nearly died before our move (it was in the box room being neglected), and this year it started bearing fruit again... so I Googled to make sure they're edible, then tasted one. Google is right: totally edible, but so tart that you probably wouldn't want to eat it. Tastes like someone bred an orange and a lemon together and all the sour of the lemon came through. Lovely aroma, though! I might use the juice in my sour mix.