Another possible origin of the term can be found in the works of H. P. Lovecraft. A short story of his, entitled "In the Walls of Eryx" and first published in Weird Tales [34, No. 4 (October 1939), pp 50-68], contains this passage:

I had encountered at least one of those curious mirage-plants about which so many of our men told stories. Anderson had warned me of them, and described their appearance very closelyâ??the shaggy stalk, the spiky leaves, and the mottled blossoms whose gaseous dream-breeding exhalations penetrate every existing make of mask...Although everything was spinning perilously, I tried to start in the right direction and hack my way ahead. My route must have been far from straight, for it seemed hours before I was free of the mirage-plant's pervasive influence. Gradually the dancing lights began to disappear, and the shimmering spectral scenery began to assume the aspect of solidity. When I did get wholly clear I looked at my watch and was astonished to find that the time was only 4:20. Though eternities had seemed to pass, the whole experience could have consumed little more than a half-hour. (link above)