In the lush caves biome, blocks can generate on top of the dripleaf plant and cut off the pad part of it.

Blocks can generate on top of the dripleaf plant and cause the top to disappear (the stem still stays) and it causes an awkward sort-of floating block that doesn't make sense. It was near a mineshaft in the screenshot, but I don't think it was colliding with the structure. It is a rare instance though.