Hawaiian Plant Threatens South Carolina Dunes by Robin Roecker and Tommy Socha photos by: Will Conner, Baruch Institute of Coastal Ecology and Forest Science

During the 1960’s, a plant was sought that would help protect and build ocean-side fore dunes in South Carolina. The plant had to be drought resistant, sand and salt tolerant, and fast growing.

Beach vitex (Vitex rotundifolia), native of Engineers, Charleston District, has to Korea, Hawaii, Japan, and China, was observed the growth of beach vitex along chosen. The prolific and resilient plant frontal dunes in South Carolina. Socha first now is taking over the natural vegetation noticed the sprawling shrub with blue- along the South Carolina shore. Beach purple flowers while working on a Corps vitex threatens native plants along primary project to replenish 25.6 miles of the South Beach vitex showing blue-purple flowers. beach dunes, including sea oats (Uniola Carolina coast from the north end of North paniculata), sweet grass (Muhlenbergia fil- Myrtle Beach to Garden City Beach. Socha Beach heading towards Hobcaw Beach. ipes), and sea beach amaranth (Amaranthus observed healthy beach vitex growing Betsy and other sea turtle volunteers have pumilus). It also threatens loggerhead sea below the high tide line, mingled among since noticed the plant spreading in or near turtles. Recent state and local newspapers native sea oats and bitter panicum. Later, turtle nesting areas, where its fibrous roots have deemed it “a predatory plant,” “a while evaluating beach vitex for use on have the potential to trap turtles and killer of sea-turtle nests,” and the “kudzu dune stabilization projects, Socha and oth- destroy eggs. of the coast.” Fortunately, major efforts are ers, including Bob Eplie and Randy Planting on the dunes in South underway to document the occurrence and Westbrooks, then with the U.S. Carolina is regulated by the state spread of the plant, to increase public Department of Agriculture’s Animal and Department of Health and Environment, awareness of its invasiveness, and to Plant Health Inspection Service, Plant Office of Ocean and Coastal Resource explore methods of control while restoring Protection and Quarantine, observed Management (DHEC-OCRM), which native beach dune vegetation. beach vitex overtaking another aggressive requires a permit before planting in dunes The South Carolina Exotic Pest Plant non-native plant, silverberry (Elaeagnus under its jurisdiction. Permits are only Council (SC EPPC) has requested a grant sp.), and creating a monoculture on the granted for planting sea oats, American from the Pulling Together Initiative (a pub- frontal dunes. They found multiple run- beach grass, and panic grass, though there lic/private partnership for invasive and ners (stolons) on the beach vitex, with is no requirement that other plants be noxious plant management coordinated by some measuring more than 10-meters removed. the National Fish & Wildlife Foundation) long. Later they learned that this location Beach vitex, also known as roundleaf to coordinate efforts to control beach vitex had been landscaped with more than 500 chastetree, chasteberry, Monk’s pepper, or in South Carolina. This effort involves beach vitex plants at the request of the kolokolo kahakai (as well as numerous cooperation among various federal and homeowner. The plant also was noticed a other Hawaiian names), typically grows to state agencies, non-profit groups, and pri- couple of years ago by sea turtle volunteer 6-8 feet in spread diameter and six inches vate landowners comprising a beach vitex Betsy Brabson, who observed it spreading to two feet tall, but can reach four feet in task force, and is a pilot for the National quickly up and down the beach in height and twelve feet in width when pro- Early Detection and Rapid Response Georgetown County, SC. Last year, Betsy tected from wind and salt spray. The round System for Invasive Plants in the U.S. documented that the plant was indeed leaves are gray-green to silvery, 1 to 2 inch- For the last eight years, Tommy Socha, spreading when she counted 167 new es long, and have a spicy fragrance. The a plant specialist for the U.S. Army Corps plants in a 0.4-mile stretch on DeBordieu flowers are typically one inch wide, bluish

WILDLAND WEEDS 19 landowner permission. More Society; the SC Turtle Volunteer network; active restoration of coastal SC Department of Parks, Recreation, and dunes is being explored. Tourism; the SC Department of Natural Beach vitex is being used as Resources; the Belle Baruch Foundation; a field test for the National Early the University of South Carolina’s North Detection and Rapid Response Inlet – Winyah Bay National Estuarine System, developed by the Research Reserve, Baruch Marine Field Federal Interagency Committee Laboratory; the SC Department of Health for the Management of Noxious and Environmental Control Office of Beach vitex going dormant. and Exotic Weeds (FICMNEW Ocean and Coastal Resource Management purple, and produced in small clusters at 2003) (see http://ficmnew.fws.gov/FICM- (DHEC-OCRM); the U.S. Fish and Wildlife branch tips throughout the growing sea- NEW_EDRR_FINAL.pdf). As part of this Service; Clemson University Departments son. The round fruits are about 1/4 inch in effort, an ecological assessment will be con- of Plant Industry; of Forestry and Natural diameter and bluish purple to black when ducted to document impacts to native plants Resources; and of Horticulture; the U.S. ripe. Vitex species are now placed in and animals and to sand dunes on South Geologic Survey (USGS); the Natural Lamiaceae, the mint family (e.g. Weakley Carolina beaches. A regulatory assessment Resources Conservation Service (NRCS); 2002); they were long considered part of will be conducted to determine if Friends of Huntington Beach State Park; Verbenaceae, the vervain or lantana family beach vitex should be listed as a state and area newspapers. (e.g., Radford et al. 1968). There are about noxious weed. 250 species of trees and shrubs in the Vitex The Charleston District of the Corps Robin Roecker is president of the South Carolina Exotic Pest Plant Council. For more information, genus, mostly tropical but a few in temper- of Engineers is in position to play an active contact her at [email protected] ate zones. Only two species of Vitex, both role in coordinating control and restora- References cited: non-native and widely sold as ornamen- tion activities on federal and state lands. Hawaiian Native Plant Propagation Database, College of tals, are known from the Carolinas: Vitex Removing the deep-rooted plant will most Tropical Agriculture and Human Resources, University of Hawaii at Manoa, pdcs.ctahr.Hawaii.edu rotundifolia and V. agnus-castus (lilac chaste likely involve herbicides; digging them out Radford, A.E., H.E. Ahles and C. Ritchie Bell. 1968. tree). may create too much disturbance in the Manual of the Vascular Flora of the Carolinas. University of Beach vitex was carried early to fragile beach dune ecosystems. North Carolina Press, Chapel Hill. NC. 1,183 pp. Weakley, A.S. 2002. Working Draft, Flora of the Carolinas Europe and used medicinally, particularly Partners with SC EPPC on the beach and Virginia. Curator, University of North Carolina as a remedy for female ailments. In Roman vitex task force include the SC Native Plant Herbarium, Chapel Hill, NC. times, women whose husbands were abroad spread the aromatic leaves on their couches to reduce sexual desire. During the Middle Ages, the berries were a food spice at monasteries, hence the names Monk’s pepper or Cloister pepper. It also was used in Europe as an important reme- dy for regulating the female reproductive system, controlling acne in teenagers, eas- ing menopausal changes, and easing pain during childbirth. According to one mod- ern herbal web site (Holistic-online.com), beach vitex stimulates and normalizes pituitary gland functions. The focus of the beach vitex task force and SC EPPC over the next couple of years will be to document the occurrence and spread of the plant along coastal dunes, to inform private landowners, local nurseries, and others regarding the invasiveness of the plant, to document impacts to native plants and animals, and to hand-pull seedlings occurring on coastal dunes, with Beach vitex showing habitat.

20 SUMMER 2004