I have a lot of garden books but only a handful are irreplaceable. One of these is The Color Encyclopedia of Ornamental Grasses by Rick Darke. So irreplaceable that I actually have a back-up copy (of course if I were smart one copy would be in a vault somewhere but I am not really methodical that way so both are in tatters). Published in 1999 by Timber Press it is still the most authoritative study of ornamental grasses that I am aware of. Darke has a couple of quick chapters on subjects such as aesthetics and nomenclature before the real fun begins: an alphabetized, detailed accounting of just about any grass you are likely to come across no matter which planting zone you are living in. With more than 500 wonderful photographs I cannot recommend this book highly enough to the casual or professional gardener. Occasionally available at used book stores.