Don't know if it's a bug, but it seems strange:
Was with a half-dragon in western jungle (dungeon with the druid boss who spawns plants).
Since the half-dragon has an magical attack, it can't no destroy the mana-burn plants. Pushing a plant into a monster or another plant destroys the plant (due to knockback). But pushing a plant into a wall does nothing. Which is strange, since monsters can be killed by pushing them into a wall.