From your picture, this is a tree-tongue ganoderma.

The tree tongue is characterized as:

Substrate perennial, lateral sessile, woody or subcorky. The cap is flattened, semicircular, fan-shaped, flat hill-shaped to low horseshoe-shaped, (5-30)cm×(6-50)cm, 2-15cm thick; the cap surface crust is grayish-white to grayish-brown, often covered with a layer of brown spore powder, with obvious concentric ring ribs and rings, often with wart-like protuberances of different sizes, and often irregularly finely fissured after drying; the edge of the cap is thin and sharp, sometimes obtuse, entire or undulate.