G-13 is the famous (some say mythical) strain supposedly developed by the United States government on their Mississippi pot farm several years ago ... there are a couple of seed banks carrying the name (Mr. Nice has a hybrid with it), but there are also weed historians that say the whole thing is just a rumor ... no way to ever know, as the government aint talkin' ... whatever it is, it had a legendary following, and supposedly the highest THC of anything "at that time" ... nowadays, I would think there is a very good chance that the White Widow strains, the new Willie Nelson, perhaps, are even higher THC, so, ... time and scientific breeding marches on !! ... :smokin: