Australian bark branches bush-tucker central-Australia cork corkbark corkwood corkwood-tree food hakea hakea-eyreana medicinal straggly-corkbark tangle tree trunk twisted adansonia gregorii Australian baobab Australian boab boab boab tree bottle tree brown-gray brown-grey cut-open dead rat tree deciduous distinctive dried dried-out exterior food-source fruit furry gadawon gouty stem tree hard indigenous Kimberley native large nut seed-pod shape shell slow-growing surface useful