The first three letters of the ancient Irish Ogam alphabet were not A, B, C but B, L, N. Every letter of Ogam had a word associated with it, and many of these words were tree-names.

B was known as Beithe ‘Birch’, L as Luis ‘Rowan’, and N as Nin ‘Ash’. The whole alphabet was often called Beithe Luis Nin.

The letters were termed feda ‘trees’, and a single letter-score was called flesc ‘twig’. The Modern Irish word for ‘hyphen’ is fleiscín.--Seanchas.