Excerpt
In the journal of the Magnolia Society (1994) Dick Figlar of Pomona, New York, related how in 1971 Francis Krenbaum had been grading a section of his land near Clarkia, Idaho, in the valley of the St. Maries River, when he uncovered the best-preserved Miocene (5-25 million years ago) plant fossil site in the world.
What he had exposed were black leaves being turned in the soft shale; some were even blowing in the wind. Charles Smiley of the University of Idaho at Moscow over the ensuing years discovered more than 130 plant species of Magnolia thought to be 17-20 million years old. As well as those trees associated with the modern-day North American flora, including species of Liriodendron, Liquidambar, Taxodium, Diospyros, Nyssa, and so on, they also found several genera confined to eastern Asia, including Metasequoia, Cunninghamia, Zelkova, and Paulownia.
Figlar related how in 1991 he and his wife, Anita, were allowed to visit the main site and to dig for fossil leaves including those of Magnolia latahensis and a second species that resembled M. acuminata. Also discovered by Smiley was an immature fruit aggregate resembling M. grandiflora. Close examination indicated nine tepals, about 250 stamens, and 120 carpels, all well within the ranges of today's M. grandiflora.