For more on the Celtic possibilities, see Robert Graves, "The White Goddess." He says the druids used MANY symbols for alphabets in code, including trees. The two lily-white boys cloth-ed all in green-ooh are supposed to be the letters D and T, which bacause of their similar sounds are represented by two kinds of oaks. And I always thought the three just referred to a love triangle: two's company, three's a crowd sort of thing. None of my professors ever heartily endorsed "The White Goddess," but it was a fun read anyway.

Chicken Charlie