So in the vanilla game grasses are cool and all, but with the exception of bamboo, good, and evil grasses are almost entirely identical. In addition, they serve no purpose from a gameplay sense, in that no resources can be harvested. So changing them all won't change anything meaningful beyond aesthetics. And personally, I like aesthetics. The mod replaces all grass EXCEPT bamboo, good, and evil grasses with generic ones. Generic as in, not a specific species. Basically it changes how biomes look. Plains, tundra, and mountains are unchanged, but forests are darker and more foreboding, swamps have are even more forebodinger and have patches of mud, and deserts have round cacti instead of grass.
HOW TO INSTALL: Just drop it into the objects folder and let it override the vanilla grass. It might mess things up if you have previously modded your grass, in which case you gotta patch things up.
It should work okay in the vanilla game but let me know if there's anything wrong.
link:
http://dffd.bay12games.com/file.php?id=14410