Classical Query: Trees Are Alphabets??

Please help Matthew McGowan, who writes in with a query:

I received a note from a poet friend about the Roland Barthes quotation from his “Roland Barthes by Roland Barthes” book (1977, p. 41):

“According to the Greeks, trees are alphabets.”

I assumed it might be from Aristotle or Theophrastus, but have not been able to find anything. Have you come across the idea of “alphabets as trees” in Greek literature before? Is Barthes simply making it up? Can you share it with the RogueClassicism community to see what others have to say?

Replies as comments welcome!