Once they covered the landscape of the US, but now the country's chestnut trees are on the verge of extinction following.
A fungus infection has wiped out all but a few thousand trees, where once there were billions.
Now scientists hope they have discovered a cure which could save one of the country's favourite trees from oblivion.
Al Jazeera's Imran Garda reports from the Appalachian Mountains in Virginia.
Source: Al Jazeera