I cannot target blocks to hoe or break. Also, there are ghost peonies.

I expected to hoe some dirt and grass blocks, plant some crops, then go mine some other blocks.

What actually happened was right clicking did not make the hoe hoe. (It did still allow me to eat food and open a door, however.) Nor did left clicking make my pickax mine; it would give one swipe, as though I was looking at the sky, and nothing more. I noticed the little black square that outlines your targeted block is missing. Also, in places where I had just broken tall grass blocks for seed, there was now the top block of a peony bush.

Steps to Reproduce:
1. Be on a grassy island.
2. Run around said island, breaking tall and short grass blocks and collecting seed.
3. Wander down to island's edge to plant some crops by the water.
4. Take out your hoe.
5. Be unable to hoe.
6. Be able to still eat food.
7. Try to mine with your pickaxe.
8. Fail.
9. Check if you can open the door to your house. (Yes, you can.)
10. Come out of your house to the horror of an island full of ghost peonies.

I tried in both 1.8.1 and 1.8, and the ghost peonies are still there. It doesn't affect my game when in creative mode, but it does when in regular mode. Help?