It is not a hallucination: the trail smells like grape kool-aid. You have not been transported back to 2nd grade or off to Jonestown. The kudzu is in bloom (left photo near mile 10). This Japanese plant was introduced across the southern U.S. in the 1930s and 40s as a forage crop, and to reduce soil erosion. Now it is considered an invasive weed.
More purple: The poke berries are getting ripe. The berries are not edible to people, although birds and wildlife can use them. This is certainly a handsome plant! The photo below was taken directly across the trail from the Kudzu.