An Etymological Dictionary of the German Language/Krieche
Krieche, f., ‘early sloe,’ from the equiv. MidHG., f., ‘early sloe-tree,’ OHG. chriehboum; comp. Du. kriek, f., ‘wild cherry.’ Phonetically it might be derived from OHG. Chriah, MidHG. Kriech, ‘a Greek,’ if *grœca could be found in MidLat. denoting the tree and the fruit. The word must hare been introduced from Italy, on account of the Lat. term (comp. Kirsche), for it is inconceivable that the Germans, of their own accord, and without foreign precedent, should lave termed the fruit ‘Greek’ because it was imported, as we assume for the moment, from Greece. At all events, the name has not yet been explained (comp. further the Fr. loan-word crèque).