A posting I put on a couple of days ago seems to have disappeared, which is annoying.
So, to sum up quickly (a) Topsie, it really doesn't matter whether or not the members of court would have recognised the wood. It was a symbol of his office. The author said it was made of apple. Just as we don't question what carat the mayoral gold chain is (or indeed whether it's really gold) it wouldn't have mattered - but the important question for me is to know whether there are other stories in which the apple wood baton is mentioned, because that will tell me where the idea might have come from.
(b) I doubt very much whether Robert Graves, ogham or the chieftain trees would have much to do with this either. The text was written at the court of Aragon by someone who came from the Languedoc. Yes, they would have known other stories and yes, there are other little oddities in the text to show this but I'm trying to track down where the little oddities occur as well to try and make sense of them.
(c) Caitlin and John Matthews are good friends of mine but unfortunately not academically qualified or well-regarded and I'm working on a PhD which means my references must be both to carry any weight. As it happens, neither have been able to assist on this in any case!
(d) It's not a pagan matter. I have consulted a friend who knows more about genuinely old, genuine traditions than anyone else I know of and she's also baffled. But it's not a pagan matter.

And just to clarify again - I'm trying to come to my own conclusions about a possible dating for the text I'm studying. It is about Arthur and contains a few things we take for granted about Arthurian stories, such as Arthur waiting for an adventure to happen before beginning a feast, and Kay being rude and bullying (and carrying an apple baton!). I'd like to find out when these things started to be "normal", as this text is possibly quite early. The author expects his listeners to know these things, because he is to some extent playing with the concepts. So, with all respect to those of you playing with my question, I really don't want guesswork, however educated the guesswork - I'm looking for solid references that I can follow up and use.

But thanks for trying - and Guest Don, what's with the rudeness?