I've used blackberries to stain rivercane. Good time of year for balckberries. They should be ready soon!
Fall is a good time to gather and boil some black walnut husks in just a little water; till the water is about boiled away. Use the thick material for staining, wood, leather and your fingers! Smear some on your hunting boots, good cover scent for traps too!
Forgot to mention the pokeweed berries!