Hymenocallis coronaria, commonly known as the Rocky Shoals Spider Lily, is a plant native to Richland and Lancaster counties in South
Carolina. Listed as a plant of national concern, this plant is imperiled statewide in South Carolina and is on Georgia’s endangered species list. For those unfamiliar with
the beauty of this rare plant, the spider lily is a bulbous breed related to the amaryllis. Its name, the “Rocky Shoals Spider Lily,” comes from its preferred habitat—rivers
in which fast-moving, well-oxygenated water passes over rocks. Such environments are found in the Saluda and the Broad rivers near the convergence that forms the Congaree River.
The rocky shoals found in these locations are prime habitats for Hymenocallis coronaria. Peak flowering usually occurs, and blooms become visible, from mid-May to mid-June
here in South Carolina. Intermittent flowering continues throughout the summer. Each plant sends up one to three flower stalks, with as many as six to nine flowers on each stalk.
Shortly after flowering, the plant will drop mature seeds into the water. These seeds sink to the bottom of the river or are carried away by currents until they subsequently wedge
themselves into a rock crevice or wash onto sandy, rocky riverbanks and begin to grow. Existing wild spider lily populations are in danger of disappearing. Their beauty attracts
collectors and plant enthusiasts. Wild collecting of plants such as these, whose natural range is so localized and sparse, can cause declines in population. Also, changes in water
flow and water quality can be of utmost concern with any aquatic species. If the water flow increases too much, an entire colony could potentially be destroyed. Too little water
flow deprives the flowers of essential seed carrying capability. Most often, changes in water flow and water quality are caused by transportation along the water way, recreational
activities, run-off pollution or use of the water for generation of electricity and/or drinking water. There is a growing need for the preservation of spider lilies due to the
decrease in native populations. For several years now, Riverbanks Zoo & Garden has been collecting seeds in an attempt find the best means of growing this plant in a nursery
In 2005, a Rocky Shoals Spider Lily preservation team was assembled consisting of the City of Columbia, South Carolina Electric & Gas Company (SCE&G), River Alliance, South
Carolina Department of Natural Resources (SCDNR), US Fish and Wildlife Service (USFWS) and Riverbanks Zoo & Garden. The team’s goal, which is also the goal of our preservation
efforts, is to reestablish spider lilies in their natural environment along stretches of the Broad, the lower Saluda and the Congaree rivers. The project’s genesis was brought
about by re-licensing the Columbia Hydroelectric project with the Federal Energy Regulatory Committee (FERC). The hydroelectric project powerhouse, currently owned by the City of
Columbia and operated by SCE&G, is situated on the Congaree River near the EdVenture museum. The River Alliance became involved since the plant is found in many spots where
the Three Rivers Greenway is being developed. The SCDNR and the USFWS maintain regulatory oversight and guidance for reintroduction of new plants and management of existing colonies.
The team has been meeting regularly for more than a year formulating a plan to propagate, grow, and replant Hymenocallis coronaria back into its native river habitat. Riverbanks’ primary
role is to lend additional expertise, collect seeds, germinate the seeds and grow them into small bulbs.
Members of the team will return these young plants to the river and monitor the new plantings.
The project, anticipated to last for ten years or more, is divided into three distinct stages. The first phase, the Pilot Study Phase, is occurring as you are reading this article,
and is expected to last for three to five years. The goal of this phase is to survey existing colonies of spider lilies and develop procedures for replanting.A small planting of
90 spider lilies was conducted in late 2006. This planting was designed as a test to determine successful methods and sites for a potentially large-scale planting. The next phase,
the Trial Planting Phase, will begin immediately after the Pilot Study Phase and will involve planting approximately 1,000 bulbs back into the wild. These populations will be monitored
on a quarterly basis to determine what percentage survives at each location. The Mass Planting Phase is the final phase. In this phase, we will use the data collected from the various
planting sites to determine how we will plant our project goal of one million or more Hymenocallis coronaria. At present, the team is hopeful for a reasonable percentage of success
(10-20% success would be fantastic). If our methodology proves successful, the plan will continue with additional numbers of spider lilies being added in the three rivers in the
coming years. Watch for the inaugural Spider Lily Festival being planned for May 2008 at Riverbanks Botanical Garden. The festival will help promote public awareness of the plight
of the spider lilies, raise money for conservation efforts and offer the community the opportunity to see this naturally occurring gem in its native habitat.
Similar to the anticipation of a spider lily producing three stalks, the team wants to achieve three results from this project: to raise public awareness of the beautiful yet threatened
populations of spider lilies within the Broad, the lower Saluda and the Congaree rivers; to bolster existing spider lily populations; and to establish new colonies of the plant.
An additional upshot will be to educate the public about the Rocky Shoals Spider Lily and demonstrate how people can help preserve a plant in the wild. Ultimately, the team believes
our efforts will allow future generations the ability to enjoy this wonderful native plant.