From Acanthaceae to Zygophyllaceae

FAYETTEVILLE, Ark. — Thanks to the work of University of Arkansas biology professor Johnnie L. Gentry and his colleagues, 351 new plant species have been recognized in Arkansas. These species and 2,356 others appear in the recently published Checklist of the Vascular Plants of Arkansas.

“We’ve collected specimens in every county in Arkansas,” said Gentry, director of the herbarium in the J. William Fulbright College of Arts and Sciences, who coordinates the Arkansas Vascular Flora Project. The project’s ultimate goal is to produce a comprehensive publication about the state’s plants — the first one of its kind. The checklist is the first of three publications to sprout from the project.

“This will serve as the foundation of the book,” Gentry said.

Many government agencies and nonprofit organizations will use the checklist to assist with updating their own lists, including the Arkansas Natural Heritage Commission, the Arkansas Game and Fish Commission, the Ouachita and Ozark National Forests, the U.S. Fish and Wildlife Service and the Nature Conservancy. The checklist also has been requested by botanists in other states, who wish to see what plants grow in Arkansas and how they have been named.

“As we conduct research, we modify the nomenclature of species and discover new species that haven’t been defined,” Gentry said. Take Gentry’s pet project, the common blackberry, genus Rubus, for example: Before researching the genus for the checklist, it was thought that 11 species of Rubus exist in Arkansas. The list now includes 18 species of Rubus, and since its publication two new species have been identified.

“These plants are newly recognized members of the Arkansas flora,” Gentry said.

Recognizing a new species involves a combination of old and new techniques. Botanists still measure the height, leaf length and width and other morphological characteristics of flowers and fruits, and examine the habitat, geology and distribution of the plant to help determine if it is a different species. They also use scanning electron microscopes to examine pollen samples, and other techniques to look at chromosomes and DNA to determine any differences that might show that the plant in question is a previously undescribed species.

All the work of examining plants in the field and the laboratory finally resulted in the checklist, which Gentry calls a “work in progress” that will continue to be updated as time goes by. The cover of the checklist shows an illustration of a plant, Sabatia arkansana, or Pelton’s rose-gentian, that was discovered by John Pelton of the Arkansas Native Plant Society. Pelton showed the plant to Theo Witsell of the Arkansas Natural Heritage Commission who believed it was a new species. Witsell sent it to J.S. Pringle, a Canadian botanist who specializes in Sabatia, and who confirmed that the plant in question was a new species never before known to science.

The checklist is alphabetized by the Latin name for the plant, followed by the common name, and information on whether the plant was introduced to Arkansas, is endemic, invasive, or a species listed by the Arkansas Natural Heritage Commission as one of special concern. The checklist includes a separate section addressing 485 plant species of special concern, which includes information on their federal and state status as either a candidate for special listing, as threatened or as endangered. This section also includes a ranking of the plant’s rarity, both at the state and global level.

The committee members have started work on the next publication, an atlas of the vascular flora, which they hope to see published by early 2008. The atlas will include information on the distribution of the flora, as well as information on the vegetation, geology and soils in the different regions of Arkansas. The atlas also will contain information on the collector and the herbarium where each sample is housed, so that researchers can return to the samples for further study if it is needed.

“This is not a static document,” Gentry said. Changes will need to be made as scientists add new species and resolve the identities of misidentified species.

After the completion of the atlas, the researchers will begin work on the comprehensive volume on the vascular flora of Arkansas, which will take about a decade to complete.

Members of the Arkansas Vascular Flora Committee include Donald E. Culwell of the University of Central Arkansas, Ronald H. Doran of Harding University, Karen Fawley of the University of Arkansas at Monticello, Linda Gatti-Clark of Hendrix College, Joyce Hardin of Hendrix College, Edith L. Hardcastle of the University of Southern Indiana, Philip E. Hyatt of the USDA Forest Service, George P. Johnson of Arkansas Tech University, Daniel L. Marsh of Henderson State University, Jewel W. Moore of the University of Central Arkansas, Sarah C. Nunn of the University of Arkansas, James H. Peck of the University of Arkansas at Little Rock, Brett E. Serviss of Henderson State University, Eric Sundell of the University of Arkansas at Monticello, R. Dale Thomas of the University of Louisiana at Monroe, Gary E. Tucker of FTN Associates in Little Rock, Staria Vanderpool of Arkansas State University and C. Theo Witsell of the Arkansas Natural Heritage Commission.