The Rare Beauty of the Rocky Shoals Spider Lily
by Alex Richardson
Rocky shoals spider lilies, Hymenocallis coronaria, were once prevalent in streams throughout the southeastern United States. As populations declined, the plant came under consideration for protection by the Endangered Species Act. Dr. Althea Hagan in the Department of Forestry and Environmental Conservation and her students in the Unraveling the Mystery of the Rare rocky shoals spider lily Creative Inquiry project are monitoring populations and trying to determine the factors contributing to the spider lily’s decline.
The rocky shoals spider lily is an important indicator species for overall stream health. Indicator species are organisms that are used to monitor the health of an environment when it is not practical to deploy water quality instruments. Streams with spider lilies growing in them are likely to be healthy. On the other hand, South Carolina streams that lack these plants may be candidates for restoration. Dam construction likely diminishes populations because it damages the natural habitat of this aquatic plant—the shallow rocky banks (shoals) of the streams. Dams may also negatively impact the flow rate of water, thus compromising overall stream health.
The Creative Inquiry team is using methods from the “Adopt A Stream” program to monitor the health of streams with or without rocky shoals spider lilies. In this program, students to measure and monitor water quality indicators such as pH, dissolved oxygen, phosphorous and nitrogen. The team is also looking at other factors such as the stream’s flow rate and soil composition. Through studying the conditions of the streams, the team expects to identify the spider lily’s ideal environment.
To further this Creative Inquiry team’s research, Hagan is applying for grants in order to purchase the equipment needed to monitor streams remotely. This will allow the team to broaden the scope of their research, expanding data collections into neighboring states. By understanding the ideal growing conditions of the rocky shoals spider lilies as well as the causes of past population decline, this team will be able to develop effective restoration efforts in streams throughout the state of South Carolina.
Barbara J. Speziale