You can look up descriptions of a lot of cover crops,
including various clovers, here:
http://www.sarep.ucdavis.edu/database/covercrops
The stuff that one typically finds in lawns is some kind of white
clover:
http://www.sarep.ucdavis.edu/database/covercrops
Clovers do come in all heights, though:
http://www.beetberry.com/BeetberryIm...verCropRay.jpg