woody leaf or leafy wood?

should i be surprised that this leaf looks so much like carved wood?  at what point does a plant transition from wood to foliage? is the massive base of a palm frond wood or leaf? alas, i suppose it is all leaf. leaves are shed. wood is not. but it wasn’t until i took this photo that i even contemplated such things. and this is why i love STILL.

bird of paradise leaf (Strelitzia reginae)