The world's longest-running seed experiment is still giving up greenery. A group of seeds buried in a secret spot at Michigan State University in 1879 have begun sprouting after they were dug up and planted in mid-April. The first sprouted April 23—"an amazing moment," per botany professor Dr. David Lowry—and was followed by 10 more sprouts, reports the New York Times. It's a continuation of an experiment started by 19th-century botanist William Beal, who was curious to know how long seeds would stay viable underground. He was "a visionary" who was "becoming more increasingly aware of what we refer to today as the seed bank," experiment caretaker Frank Telewski tells Michigan Radio's Stateside. Now, every 20 years, scientists dig up Beal's bottles and plant the seeds within. Verbascum blattaria, a nonnative weed Beal is thought to have mistaken for Verbascum thapsus, has been reliably germinating over the course of the last century.
Ten of the sprouts appearing this spring are V. blattaria. But one "is a bit of a mystery, with leaves that are hairier and sharper-edged than those of the other sprouts," per the Times. Scientists still need to identify the species and confirm the remaining seeds aren't viable. That will mean testing a cold treatment—which prompted the germination of the only non-Verbascum plant in 2000, from a Malva pusilla seed—a smoke bath, and a plant growth hormone. They may also try roughing up the seeds. Telewski, a professor of plant biology, says scientists are also preparing a follow-up to this experiment, which is expected to end when the last of Beal's bottles is unearthed in 2100. This time, scientists will do a baseline check of the number of seeds that germinate when immediately planted—something Beal didn't do. They might even use seeds from this year's sprouts. (Read more science experiment stories.)