The ultimate magic mushroom.
http://news.nationalgeographic.com/news/bigphotos/2664113.htmlThe enigmatic plant fossil Prototaxites from the Silurian-Devonian has been confirmed by isotopic evidence to have been a gigantic fungus. At over 8m tall this would have been the tallest thing on the planet at the time. To see the ancient otherworldly landscape dominated by these giants would have seemed a bit like living through the hallucigenic effects of some of their modern-day cousins.