Mealy Tooth

Hydnellum ferrugineum, commonly known as the mealy tooth or the reddish-brown corky spine fungus, is a species of tooth fungus in the family Bankeraceae. A widely distributed species, it is found in north Africa, Asia, Europe, and North America. The fungus fruits on the ground singly or in clusters in conifer forest, usually in poor (low nutrient) or sandy soil. Fruit bodies are somewhat top-shaped, measuring 3–10 cm (1–4 in) in diameter. Their velvety surfaces, initially white to pink, sometimes exude drops of red liquid. The lower surface of the fruit body features white to reddish-brown spines up to 6 mm long. Mature fruit bodies become dark reddish brown in color, and are then difficult to distinguish from other similar Hydnellum species. H. ferrugineum forms a mat of mycelia in the humus and upper soil where it grows. The presence of the fungus changes the characteristics of the soil, making it more podzolized.

Excerpt from the Wikipedia article Hydnellum ferrugineum, by its authors, under the CC BY-SA 4.0 licence.