You may recall last week I wrote about a family amused to see a dish of haricot beans at their Spanish hotel labelled "Jewish with ham" – the literal translation of judias con jamon. Judia can mean both a Jewish woman and bean in Spanish.
Here is one explanation via the internet. In Spanish, arbol judia means bean tree or Judas tree (the tree on which Judas Iscariot was said to have hanged himself). The tree produces bean-like pods, so judia could have come to be used for green beans when they arrived in Spain. Alternatively, the tree's name could have been derived from the fact that it grew widely in Judea.