A very late good evening David.
Yes, there does seem to be a good bit of tree lore in there, doesn’t there? I’ve also heard superstitions about it being bad luck to cut or burn alder, something about the tree that bleeds – the sap inside. However, these may well be from different traditions and different epochs, so we need to be careful about drawing any conclusions – I know, I always say that! 😀 Nevertheless, freshly cut alder does smoke a lot too, so it might have a more profane origin. Who knows with these beliefs? It’s like black cats, lucky in Britain and Ireland, but unlucky just about anywhere else! I’ve also got an inkling that these woods to be burned or not burned may refer to something a bit deeper than firewood, but I’m still researching that.
They are indeed mostly Ogham trees, even though this does not make any reference to Ogham nor is the story from which it comes Ogham related. I thought you might appreciate the line about the willow. I’m intrigued by rowan being the druid’s (?) tree and there is indeed a lot of folklore about rowans being a powerful tree against witchcraft and suchlike. The reference to the elder and the sidh is also very interesting too and the sacred yew is something that I think we’ll recognise from the British Isles and Ireland straight away.
Anyway, I’m glad you found this interesting and I hope the Old Irish was useful to you too. If you follow the links, you can find a vast corpus of Irish materials in the Silva Gadelica, something which I’m very glad to have “discovered”. I’m still working on the calendar material – it’s a bit more complicated than it seemed at first!