Southern magnolia (Magnolia grandiflora)
"This stately magnolia is one of the most conspicuous trees of the southern woods, occasionally attaining a height of seventy feet. […] Today the members of the Magnolia Family found in America are but a remnant of the numerous species that flourished in pre-glacial times from the mid-continental plains to the Arctic Circle. The fossilized trunks found at Amethyst Mountain in Yellowstone Park, with specimens of both fruit and leaves, give an indication of their grandeur and beauty in former ages."
This illustration and the description are from "North American wild flowers" by Mary Vaux Walcott. (Published by The Smithsonian Institution, 1925)