adansonia-gregorii Australian-baobab Australian-boab barrel-trunk boab boab-tree bottle-tree brown-gray brown-grey dead-rat-tree deciduous distinctive gadawon gouty-stem-tree grotesque indigenous Kimberley-native large shape slow-growing smooth-bark soft-fibrous-wood surface surfaces texture textures trunk useful water-retention adansonia gregorii Australian baobab Australian boab barrel trunk boab tree bottle tree dead rat tree gouty stem tree Kimberley native road verge smooth bark soft fibrous wood verge water retention cream flower flowers fruit furry nut white damage damaged diseased pitted recovery repairing self-repairing wounded wounds