Mushrooms growing on leaf blocks in tree

Saw mushrooms (small type) spawning normally in some forests in darker areas. Crested a rise in "Taiga" and saw a multi-tier "spruce" with mushrooms on the ground under it, but also on two tiers of its "leaf" blocks.

On the plus side, gave me and a friend an idea for "fungus" or "lichen" that grows like cacao beans on the side of spruce instead of jungle wood.