Minecraft wiki entry for Removed_blocks, associated text: Unlike the dead bush, which was a separate block and used a separate block ID at the time, the shrub was the default data value variant of the block ID that also hosted grass and ferns, which were respectively metadata values 1 and 2 of the shrub. As such, the shrub inherits much of the functionality of grass and ferns; alongside the aforementioned offset, they also had the same chance to drop wheat seeds upon breaking.