This bug first appeared in build 1.7.10-2.1.0.1609, when Better Foliage support was added. It happens whether Extra Leaves is enabled in Better Foliage or not. Vanilla leaves are fine.

It seems to happen with every version of Better Foliage I've tried. The only way to get the leaves to render normally is to completely remove Better Foliage or downgrade Biomes O' Plenty to before build 1.7.10-2.1.0.1609.

• Minecraft Version: 1.7.10
• Forge Version: 10.13.4.1614-1.7.10
• Mods List: Biomes O' Plenty build 1.7.10-2.1.0.1609 or newer, Better Foliage MC1.7.10-2.0.3.