Fulton Neighbor
January 23, 2026

By Rachel Kellogg

A newly discovered species of Arisaema has been named in honor of Atlanta Botanical Garden horticulturist Scott McMahan.

McMahan, manager of the garden’s international plant exploration program, along with a team of Vietnam scientific partners discovered the unnamed species while conducting field research in 2024.

The plant, discovered in Vietnam, has been named Arisaema mcmahanii in recognition of McMahan.

“When I heard that my colleagues in Vietnam had named this Arisaema after me, I was stunned,” he said in a statement. “We have been working together for almost 20 years and have had many wonderful exped itions as a team, so this is a huge honor for me personally and a testament to the partnership we have created.”
McMahan’s namesake plant was recently recognized as a valid new species according to scientific peer review and DNA evidence.

Arisaema is a diverse genus of flowering plants with the largest concentration of the species found in China and Japan, while other species are native to southern Asia, central Africa, Mexico and eastern North America. Asiatic species are often called cobra lilies, while western species are known as Jack-in-the-Pulpit. Both names refer to the flower’s erect central spadix rising from a spathe.

How the discovery happened
In 2019, the Vietnam Academy of Science and Technology team that typically collaborates with the Atlanta Botanical Garden’s international plant exploration program was on a field trip in southern Vietnam to study Aroids — the plant family that includes Arisaema. While collecting plant material in Chu Mom Ray National Park, the team found a specimen that appeared different from those they were seeing in the area. A sample was collected and taken back to Hanoi to be studied. Based on morphological characteristics of the specimen, it was believed to be an undescribed species.

Five years later, the garden’s team joined their Vietnamese colleagues on an expedition to Gia Lai province in the central highlands to look for Magnolia species. During this trip, the group again came across a group of Arisaema that looked identical to those found previously in Kontum province. This time, bulbs were collected and taken back to both the Vietnam Academy of Science’s Biodiversity Station as well as the Garden.

A new species is born
Once the plants began to bloom in cultivation, it became apparent they were possibly a new species, a news release said. DNA samples were collected and sent to Aroid experts at the Royal Botanic Gardens, Kew in London for verification. Kew acknowledged that the submitted sample is Arisaema sp. Nova — or a new species to science.

McMahan, who has been working with the Vietnam team since 2007, has led the garden’s efforts there since the beginning of the long-term, collaborative relationship. In recognition of the Garden’s commitment to the partnership, the Vietnamese researchers chose to name the newly discovered species of Arisaema in honor of him. The discovery will be published in the Vietnam Academy of Science and Technology Academia Journal of Biology.

About the program
The garden’s international plant exploration program was established in 2016 to collaborate with international gardens and institutions to help preserve plant species and evaluate new ones for use in southeastern U.S. landscapes. Plants from southeast Asia have long been reliable components of southeastern gardens because of the comparable climates. The program’s key components have been to develop a plant evaluation nursery at the Atlanta Botanical Garden, Gainesville, make formal seed-collecting trips to southeast Asia and sponsor an annual visiting scholar program.

Photo: Arisaema mcmahanii. the new plant species, was discovered in Vietnam.