Flowers can share a space with arbitrary blocks

How to reproduce

1. Place a flower on grass
2. Place a snow layer in the same space as the flower
3. Place any non-full block (e.g. a slab), replacing the snow layer

   

   

 

When some blocks are placed, the flower is simply deleted. Examples: other flowers, full blocks.

When some blocks are placed, the snow is removed and nothing else happens. Examples: mob heads.