- Clumps of adventitious sprouts or shoots develop below cankers on large branches
- Leaves growing beyond the canker turn yellow and wilt (Siberian elm) or fall off (American elm)
- Reddish brown to black water soaked cankers form on branches 4 inches in diameter or smaller
- Sap wood underneath the canker is reddish brown
- Tiny raised pimple like fungal structures form on branches killed by the canker, causing bark to look rough
- Damage is most severe on trees stressed by other factors
- More information on Botryodiplodia canker...