2 block high plant peony bug

Every time on Minecraft 1.8, when you destroy a 2 block hight plant such as lilac, double tallgrass, large fern, sunflower, rosebush and peony themselves.
It quickly flashes a top half of a peony flower and quickly disappears this happens with all of the plant listed above.
This is shown in the picture attached.

Thank You for you time.
Ginja