Southern magnolia seeds (Magnolia grandiflora)
"As early autumn approaches, the fruit of the southern magnolia becomes conspicuous, and as it ripens the outer envelope cracks over each seed compartment and the crimson seeds protrude from their downy coverings. […] As time passes, the seeds loosen from the shell, but are still attached to the conelike fruit by a slender white thread about an inch long, finally dropping to the ground when the wind blows them loose. Southern magnolia is found native throughout the Southern States, from Texas to Florida, northward to Arkansas and southeastern North Carolina."
This illustration and the description are from "North American wild flowers" by Mary Vaux Walcott. (Published by The Smithsonian Institution, 1925)