Little American chestnut saplings can resprout from a dying American chestnut tree stump - they actually originate from the living root collar, which is part of the stump. These new trees are called collar sprouts.
American chestnut collar sprouts are special. They are stronger than the ordinary stump sprouts of other trees because they quickly develop their own root systems.
Collar sprouts help demonstrate why American chestnut became so numerous before the blight - each collar sprout could grow into a giant tree from the stump of a chopped-down or fallen American chestnut tree.
Although collar sprouts can develop from American chestnut stumps, today, nearly all become infected with the blight and die before producing nuts.