Steve Stephenson uses a key to unlock one of the nine tall metal doors that protect the largest collection of slime molds in the United States.

Inside are neatly stacked cardboard shelf boxes with labels such as “Alaska” and “Montana” and “Western United States.” They hold just a small portion of the roughly 40,000 specimens of slime molds at the University of Arkansas.

Stephenson, a research professor of biological sciences at the U of A, pulls out one of the shelf boxes to show that inside are rows of matchbook-sized boxes, each carefully labeled to describe where the specimen was collected, the date it was collected and the ecological habitat in which it occurred.

Stephenson slides open a small box to reveal a slime mold he collected in Alaska. He found Hemitrichia clavata on decaying wood in a cottonwood forest outside of a ghost town north of Nome named Pilgrim Hot Springs. The latitude and longitude are noted, as is the date: Aug. 3, 1995.

Steve Stephenson in his lab at the University of Arkansas. | Matt Reynolds, University of Arkansas

Steve Stephenson has been collecting myxomycetes for decades. | Matt Reynolds, University of Arkansas

In the future, the information on this box, and thousands like it, will be online. Stephenson, with funding from the National Science Foundation, is supervising the digitization of 10,000 of the specimens of slime molds housed at the U of A.

The three-year project is part of an overall NSF effort to digitize data for millions of biological specimens. The U of A myxomycetes will be added to the National Resource for Digitization of Biological Collections database, making them accessible to scientists, educators and the public. In some instances, an image of the actual specimen representing the collection also will be added to the database.

Slime molds are not plants or animals but they share the characteristics of both. They feed on the microorganisms associated with dead plant material, especially bacteria and fungi, and they play an important role in vital ecosystem processes such as nutrient cycling. Myxomycetes, are commonly found in soil and on dead wood and leaves on the forest floor.

The myxomycete collection at the U of A includes more specimens from some regions of the world – such as subantarctic islands and Australian deserts – than in any other collection.

“Digitizing our myxomycetes will allow researchers to examine patterns of distribution in these organisms,” Stephenson said. “For example, I plan to work with several of my colleagues on a project that seeks to evaluate possible changes in the distribution of particular species of slime molds that can be linked to global climate change.”

The slime mold collection at the U of A has more than 40,000 specimens. | Matt Reynolds, University of Arkansas

There are more than 40,000 specimens of slime molds tucked into boxes in the U of A collection. | Matt Reynolds, University of Arkansas

Stephenson is part of the Microfungi Collections Consortium, a project funded by a grant of $996,000 through the NSF’s Advancing Digitization of Biodiversity Collections program. The consortium brings together 38 institutions in 31 states to digitize their microfungi records, spurring new research and insights into these important organisms.

Since his first major international collecting trip to India in 1987, Stephenson has traveled around the world to find and record slime molds, which are abundant and integral to the functioning of our ecosystems, but rarely given a second glance on a nature hike.

“The slime molds I find to be most interesting are the rare species known from just a few specimens collected in some remote region of world,” he said. “A number of these are species that were first discovered on expeditions to such places as the isolated islands of the subantarctic, the exceedingly dry deserts of extreme eastern Peru or the tropical rainforests of Southeast Asia.”