White nodules on birch

White nodules on birch

Observation - White nodules on birch. Description: All the young silver birch saplings at this location were covered with these white nodules. Is it a fungus or something else? It's calcareous grassland on the site of an ancient quarry.

All the young silver birch saplings at this location were covered with these white nodules. Is it a fungus or something else? It's calcareous grassland on the site of an ancient quarry.