Leaves.. bark.. branches..

Can the main body of the timber from fallen trees be extracted?
What parts are best?

In theory the root bark, which is the bark underneath the soil, is the most potent and the higher up you get the less it will yield - ie the bark has more than the branches and the branches has more than the leaves. So, the bark.

Are you in Australia?

yep.

Any idea with the mulgas?

Has anyone used any of the mulga species for extraction before?

Acacia Aneura (mulga): "Ash used in Pituri.[22] Ether extracts about 2-6% of the dried leaf mass.[23] Not known if psychoactive per se."

Doesn't seem hopeful..

What area of Aus are you from?