Looks like double high plant growth got broken. Take some grass use bone meal on it to grow it into a double block high grass. The top block will be missing completely at first I thought this was my texture pack causing this only to find out its specific to spigot 1.8.3. First elimated texture pack by using default, then started at vanilla 1.8 server and worked up.. Apparently starting with 1.8.3 vanilla it appears. I would report this as a bug but after looking into it more it seems to be specifically a vanilla inherited issue so instead of holding my breath on Mojang fixing it I'd rather ask it to be a feature/fix here. ^_