Manna gum is a eucalyptus tree native to Australia. At certain times of the year and under some conditions, the leaves of the manna gum may carry a potential poison. If these leaves are eaten, they will be broken down by digestion into a poisonous substance. This substance may be further converted to hydrocyanic acid (cyanide). Browsing animals, such as koalas, seem to be aware of this danger, and switch to other trees when this is likely to happen.
Manna, from which the tree is named, is not poisonous. It is a sweet, white substance occurring on the leaves and buds. It was used by the Aboriginal peoples of Australia to make both a sweet drink and food.
