Growth at base of Common Ash

Growth at base of Common Ash

Observation - Growth at base of Common Ash. Description: Can anyone identify this please. It is growing at the base of a lot of Ash trees. It is easy to rub off. I intend to coppice these trees. Will it suppress the growth of new buds. Thanks.

Can anyone identify this please. It is growing at the base of a lot of Ash trees. It is easy to rub off.

I intend to coppice these trees. Will it suppress the growth of new buds.

Thanks.