Allegheny chinkapin, European chestnut, Japanese chestnut, Chinese chestnut, and American chestnut burs

Note that the Chinese bur looks small, even though the nuts inside are large. This is because of their short, stubby spines.

Chestnut burs have two sutures and
open into four valves (sections)

There are up to three nuts per bur

Chinkapin burs have one suture and
open into two valves (sections).

There is only a single nut per bur