jean-claude:
>The barks used in medicinal preparation are the inner bark ( the living
>tissue) not the dead tissue commonly called bark, and in a fresh state
>are very tender to eat ( like fir inner bark used as a food by the
>natives here) For seeds if they are so hard that you can't bite into it,
>i don't think we are meant to ingest them, ...

Tom:
Hard bark and  wood is sometimes used medicinally - usually in
powder form. Sandalwood powder is used in Ayurveda, as is the
essential oil (which is bitter and a powerful diuretic in
large doses). Mangrove bark, and wormwood come to mind as well.

A powerful medicine used in Ayurevda is dashamoola, which is
literally "ten roots" and is wood. It is ground to powder
and consumed or tea is made from it. Mahasudarshan churna is
yet another medicinal blend that is ~50% tree bark, which is
one of the most bitter substances on the planet. [I have
tasted all the above - most are unpleasant in taste.]

So, although you personally would not eat wood, some types of wood are
used medicinally.

Tom Billings