U.S. Fish and Wildlife Service Southeast Region Inventory and Monitoring Branch
I&M Branch RFP Final Report
Title: Floristic Inventories of National Wildlife Refuges within the South Carolina Lowcountry and Savannah Complexes
Photo by Keith A. Bradley (Narrowleaf pondlily, Waccamaw NWR)
Prepared by: Keith A. Bradley
Project ID: PO_ F17PX02643-Fund Source-#178F1611MD and 190F1611MD
Report Date: September 30, 2019
U.S. Fish and Wildlife Service Southeast Region Inventory and Monitoring Branch I&M RFP Final Report
Title: Floristic Inventories of National Wildlife Refuges within the South Carolina Lowcountry and Savannah Complexes
Principal Investigator: Keith A. Bradley, Botanist, 1000 Natchez Trail, West Columbia, South Carolina, 29169 ______
ABSTRACT: The floristic diversity is generally unknown in national wildlife refuges in the Southeastern Coastal Plain. Eleven refuges in South Carolina and Georgia in the Savannah and South Carolina Lowcountry refuge complexes were surveyed in an effort to catalogue all plant species in each refuge. All rare plant species encountered were mapped, and for each population its size, habitat characters, and threats determined. Floristic diversity ranges widely across the refuges, from a low of 75 at Wolf Island, to a high of 1100 at Savannah NWR. Five At-risk plant species were recorded; these were found on three refuges, Ernest F. Hollings ACE Basin, Savannah, and Waccamaw. Populations of state-tracked rare plant species were found at all eleven refuges. Major threats to rare plant species on national wildlife refuges included sea level rise and associated saltwater intrusion, invasive pest plants, and feral hogs. ______
INTRODUCTION The Sea Islands/Coastal Marsh Level IV Ecoregion stretches along the southern Atlantic coast from Horry County, South Carolina to the St. Johns River in northeastern Florida (Omernik and Griffith 2008). This region represents the lowest elevations in Georgia and South Carolina, and contains environments influenced by oceanic wave, salt wind, and river actions. Habitats that are found in this geography include maritime uplands dominated by live oak and cabbage palmetto; shrublands dominated by wax-myrtle and yaupon; and tidal salt, brackish, and freshwater marshes dominated by a variety of wetland graminoids, shell middens, beach dunes, and more inland habitats such as bottomland forests and longleaf pine savannas. This geography has experienced extreme levels of land conversion over many centuries, including the alteration of native riverine and estuarine wetlands for agriculture; widespread elimination through land clearing, logging, turpentining, and fire suppression of longleaf pine woodlands; and increased housing development pressure along maritime fringe zones. Current threats to ecosystems within the Sea Islands/Coastal Marsh Ecoregion include increased residential and commercial development pressure, disruption of riparian and estuarine processes due to dredging activities, impacts from sea-level rise, and invasion of exotic plants and animals.
There are two refuge Complexes—the Savannah Refuge Complex and the South Carolina Lowcountry Complex—that manage the eleven refuges in this project, that are within and directly adjacent to the Sea Islands/Coastal Marsh Ecoregion. Of the 46 petitioned and candidate plants that occur or ‘could’ occur on refuges in the Southeast Region, 19 are within the range of
Lowcountry and Savannah Refuge Complexes Floristic Inventories 3 these two Complexes of refuges. There are also four Federally listed species that occur within the ranged of the two refuge Complexes. Table 1 lists these species, and known refuge occurrences.
From 2016-2017 seven of these refuges were surveyed for rare plant species, with a focus on At- risk taxa (Bradley 2008). That survey detected five At-risk plant species as well as 55 state- tracked rare plant species. In addition, incidental observations of unusual plant species were made in these refuges, such as new state-records of potentially invasive exotic species, and native species that should be considered for tracking as rare. Compilations of the entire flora of each refuge would help to address the full status of all native and exotic species in these refuges.
Table 1: Federal At-Risk and Listed Species in the Range of the Savannah and Lowcountry Refuge Complexes
Scientific Name Common Name Status Amaranthus pumilus Seabeach amaranth Threatened Amorpha georgiana Georgia leadplant At-Risk Coreopsis integrifolia Ciliate-leaf tickseed At-Risk Dionaea muscipula Venus flytrap At-Risk Eupatorium paludicola Swamp justiceweed At-Risk Fimbristylis perpusilla Harper's fimbristylis At-Risk Forestiera godfreyi Godfry's privet At-Risk Isoetes hyemalis Evergreen Quillwort At-Risk Lindera melissifolia Pondberry Endangered Lobelia boykinii Boykin's lobelia At-Risk Ludwigia brevipes Long Beach seedbox At-Risk Ludwigia ravenii Raven's seedbox At-Risk Macbridea caroliniana Carolina birds-in-a-nest At-Risk Minuartia godfreyi Godfry's stitchwort At-Risk Nuphar sagittifolia Yellow pond-lily At-Risk Ptilimnium ahlesii Carolina bishopweed At-Risk Rhynchospora thornei Thorne's beaked-rush At-Risk Rudbeckia heliopsidis Sun-facing coneflower At-Risk Schwalbea americana American chaffseed Endangered Scutellaria ocmulgee Ocmulgee skullcap At-Risk Sideroxylon thornei Georgia bully At-Risk Sporobolus teretifolius Wireleaf dropseed At-Risk Tiedmannia canbyi Canby's dropwort Endangered
The objectives of this project are to: 1) Compile floristic inventories for a series of two National Wildlife Refuge Complexes- Savannah and South Carolina Lowcountry (Table 2) 2) Continue to map occurrences and density of rare, at-risk, and federally listed vascular plants 3) Describe the specific environmental and vegetation attributes associated with each targeted rare species 4) Identify immediate threats, including locations of invasive species, to rare species populations 5) Document new populations of invasive species and make recommendations for invasive management priorities for new occurrences 6) Recommend management and conservation measures
Lowcountry and Savannah Refuge Complexes Floristic Inventories 4 STUDY AREA There are two refuge Complexes that manage the eleven distinct refuges in the study, the Savannah Refuge Complex and the South Carolina Lowcountry Complex, all within the Coastal Plain. These range some 300 km from McIntosh County, Georgia, to Horry County, South Carolina. Ten are within the Sea Islands/Coastal Marsh Ecoregion in the Southern Coastal Plain (Table 2, Figure 1). One refuge, Santee NWR, is more interior, within the Southeastern Plains Ecoregion. These refuges support a wide variety of ecosystems, both natural and artificial, including wet savannas, bottomland forests, freshwater marshes, blackwater streams, tidal freshwater marshes, tidal marshes, upland forests, pine savannas, dunes, and coastal shell middens. Several refuges (i.e. Savannah, ACE Basin, and Waccamaw) have areas that were historically converted to rice plantations resulting in the extensive construction of levees and water control structures to form impoundments. These remnant rice impoundments have created unique wetland ecosystems within the freshwater tidal marsh zone.
Table 2: National Wildlife Refuges in Study
Refuge State Complex Wolf Island Georgia Savannah Blackbeard Island Georgia Savannah Harris Neck Georgia Savannah Wassaw Island Georgia Savannah Savannah Georgia, South Carolina Savannah Tybee Island South Carolina Savannah Cape Romain South Carolina Lowcountry Ernest F. Hollings ACE Basin South Carolina Lowcountry Pinckney Island South Carolina Savannah Santee South Carolina Lowcountry Waccamaw South Carolina Lowcountry
Figure 1: Locations of Refuges in Study
Lowcountry and Savannah Refuge Complexes Floristic Inventories 5 METHODS Prior to field surveys data on rare plant species potentially occurring on new study refuges (Blackbeard, Tybee, Wassaw, and Wolf Island) were compiled from state heritage programs, online sources, literature, and knowledgeable individuals. Of particular importance was the SERNEC database (sernecportal.org), containing digitized herbarium specimen records from all major southeastern herbaria. Data available from state heritage program was compiled, including that by the South Carolina Department of Natural Resources (SCDNR) and Georgia Department of Natural Resources (GADNR). Additional data were searched for in published literature, gray literature, and field trip reports by the South Carolina Association of Naturalists. Any floristic data that was found for refuges was compiled into a relational database and nomenclature standardized.
Floristic data were compiled from several sources. Data from published and unpublished plant inventories for individual refuges, when available, were databased. Herbarium specimens were searched for on the SERNEC database (sernecportal.org) and databased. Other smaller sources were also used, including verifiable records on iNaturalist.org. All of these data were compiled into a relational database and taxonomy standardized, generally following Weakley (2015).
For each refuge potential search habitats were identified by analyzing available data sources to determine landscape features. Important resources included aerial photography (true color and infrared), LIDAR, and vegetation maps, when available.
Between September 2016 and September 2019 field surveys were conducted at regular intervals throughout the growing season. All surveys were conducted by the author, sometimes accompanied by refuge staff, or by Dr. John Nelson (University of South Carolina). As much of each refuge as possible was visited. As many habitats as possible in each refuge were surveyed to capture floristic diversity. In many refuges the use of boats enabled access to more remote and little studied areas.
All vascular plant species that were observed were recorded growing wild in each refuge, including native and exotic taxa. No attempt was made to catalog species cultivated at refuges. Appropriate habitats were searched opportunistically for rare plant and animal species, including At-risk species, Federally-listed species, in South Carolina refuges those tracked by SCDNR, and in Georgia refuges those tracked by GADNR. Other unusual plant species were also recorded and mapped, including untracked rare species, unusual exotic species, and new distributional records such as state records. Some locations with diverse, higher quality habitats were visited multiple times to find species with different flowering periods. Nearly all populations of previously known plant populations were revisited.
All rare species found were mapped with a Garmin GPSMAP 64 GPS unit. Individual plants were counted or population size estimated. For each rare species surrounding habitat characteristics were recorded to allow classification following either United States National Vegetation Classification (USNVC 2017) or the Carolina Vegetation Survey classification (Schafale 2012), and associated species noted. Plants or stems were counted, or, for larger colonies, estimated following a log10 scale. Threats to each population were identified.
Lowcountry and Savannah Refuge Complexes Floristic Inventories 6 Herbarium specimens were made for rare plant species when collection did not threaten populations. Specimens are deposited at the A.C. Moore Herbarium, University of South Carolina, in Columbia (USCH). Nomenclature of plant species in this report follows Weakley (2015). Herbarium specimen citations in this report include collector surname, collection number, and herbarium citation following Index Herbariorum (Thiers 2019). Heritage Program rankings follow the most recent data available on the web sites of the South Carolina Department of Natural Resources (SCDNR), Georgia Department of Natural Resources (GADNR), and for global conservation rankings NaturServe.
RESULTS Field surveys were initiated in September 2016 and continued through September 2019. Rare species data for the September 2016 to November 2017 field season are found in Bradley (2018). Only newly discovered rare species are presented here.
Refuges ranged widely in total species richness, correlating to refuge size and habitats. Species richness ranged from high of 1100 taxa at Savannah NWR, to a low of 75 at Wolf Island NWR. Bradley (2018) details the discovery and mapping of five At-risk species. These were found on 3 refuges (Table 3). In the 2019-2018 season no new At-risk species were encountered, but new populations of four of the five species (excluding Macbridea caroliniana) were found and mapped. Also, 69 species of state-tracked rare plant species were found, and records of 19 other rare species were found. All refuges contained tracked rare plant species. Summaries of findings by refuge are given below (Table 4).
Table 3: At-Risk Species Found in National Wildlife Refuges
Scientific Name Common Name Refuges Coreopsis integrifolia Chipola dye-flower ACE Basin Isoetes hyemalis Wintergreen quillwort ACE Basin Macbridea caroliniana Carolina birds-in-a-nest ACE Basin Ptilimnium ahlesii Carolina bishopweed ACE Basin, Savannah, Waccamaw Nuphar sagittifolia Narrowleaf pondlily Waccamaw
Table 4: Floristic Summary
Refuge Species Exotic EPPC USFWS USFWS State T&E At-Risk Tracked Blackbeard Island 295 17 (5.8%) 5 0 0 4 Cape Romain 503 84 (16.7%) 21 1(T) 0 13 Ernest F. Hollings ACE Basin 856 125 (14.6%) 25 0 4 17 Harris Neck 484 94 (19.4%) 21 0 0 4 Pinckney Island 408 85 (20.8%) 16 0 0 9 Santee 707 146 (20.7%) 32 0 0 12 Savannah 1100 241 (21.9% 49 0 1 37 Tybee Island 173 50 (28.9%) 11 0 0 1 Waccamaw 849 128 (15.1%) 29 0 2 24 Wassaw Island 270 29 (10.7%) 6 0 0 2 Wolf Island 75 3 (4.0%) 1 0 0 1
Lowcountry and Savannah Refuge Complexes Floristic Inventories 7 Summary of Findings by Refuge
Blackbeard Island National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge. Very little botanical activity has been conducted in the refuge. Botanists who have collected there include Marie and E.O. Mellinger (1958-1961), Don Drapalik (1971). Moonyean Brower (1984), and David Almond (date unknown). GADNR did not have any element occurrence records in their database for the Refuge, but Tom Patrick (GADNR) did report seeing Hibiscus grandifloras (personal communication 2017).
This refuge was not included in Bradley (2018) and all visits were made in 2018-2019. Surveys were conducted across Blackbeard Island. The flora of the refuge consists of 295 species. Of these 17 (5.8%) are exotic, and five of these are listed by GAEPPC.
Four State-tracked rare plant species were been found (Table 5, Figure 2). Another, Vigna luteola (S2S3) may have been seen in 2017 along Toar Savanna Dike, in association with Hibiscus grandiflorus. Plants were never observed in flower so its identify could not be confirmed. Andropogon brachystachys (S1?) is reported for the island based on a herbarium specimen (Mellinger 2706, GAS) collected in 1959 on the edge of the refuge yard. This specimen has not been observed, but is likely to be misidentified based on its habitat preferences and range.
Table 5: Rare Plant Species of Blackbeard Island NWR
Scientific Name Common Name Recorded USFWS GADNR Global Status Carex dasycarpa Velvet sedge Yes S3 G4? Eleocharis montevidensis Sand spikerush Yes S3? G5 Hibiscus grandiflorus Large-flowered Yes S2 G4? hibiscus Phyla lanceolata Marsh frogfruit Yes S2? G5
Lowcountry and Savannah Refuge Complexes Floristic Inventories 8
Figure 2: Rare Plants of Blackbeard Island NWR Cape Romain National Wildlife Refuge This refuge has a published plant inventory covering the flora of Bulls Island (Stalter, 1984) which included 268 species. The Refuge has also received attention from other botanists. Notable collectors include Bill Baldwin (1938), and George R. Cooley (1951).
Surveys were conducted across Bulls Island. Surveys were conducted on Lighthouse Island around the lighthouse, and on the mainland in the vicinity of the boat landing. The flora of the refuge consists of 503 species. Of these 84 (16.7%) are exotic, and 21 of these are listed by SCEPPC.
No At-risk species were found. This refuge is known to have had colonies of the Federally Threatened Amaranthus pumilus on Bulls Island, Cape Island, Lighthouse Island, Raccoon Key, and Sandy Point. New colonies of this species were not detected. There are currently no wild individuals of this species in the refuge, but a reintroduction program is underway (A. Punsalan, personal communication, 2017).
Thirteen State-tracked species have been found. One of these was discovered in the 2018-2019 field surveys (Eupatorium anomalum), and one has recently been listed by SCDNR (Phyla lanceolata) (Error! Reference source not found., Figure 3). New additions are indicated with an asterisk (*).
Lowcountry and Savannah Refuge Complexes Floristic Inventories 9 One species that was found, Cyperus lanceolatus, is a new record for South Carolina. It is native to the south, including Georgia and Florida. This small sedge was found in a frequently mowed wetland just southeast of the Dominick House. A new species of mint, Trichostema nesophyllum was formally described and named in 2019 and its range includes the northern portions of the Refuge (Weakley et al., 2019).
Table 6: Rare Plant Species of Cape Romain NWR
Scientific Name Common Name Recorded USFWS SCDNR Global Status Amaranthus pumilus Seabeach amaranth No Threatened S1 G2 Canna flaccida Golden canna Yes S2 G4? Carex hyalinolepis Shoreline sedge Yes S2 G4G5 Cyperus distinctus Swamp flatsedge Yes S1 G4 Cyperus tetragonus Four-angled flatsedge Yes S2 G4? Eupatorium anomalum* Anomalous Yes S1? G2G3 Eupatorium Ipomoea imperati1 Beach morning-glory Yes SNR G5 Muhlenbergia sericea Dune hairgrass Yes S3S4 G5T5? Phyla lanceolata* Marsh frogfruit Yes SNR G5 Sagittaria weatherbiana2 Weatherby’s Yes S1 G3T3T4 arrowhead Spiranthes laciniata Lace-lip Ladies'-tresses Yes S1S2 G4G5 Symphyotrichum elliottii Southern swamp aster Yes S3 G4 Trichostema nesophyllum Dune blue curls No SNR - Tridens chapmanii Chapmans triodia Yes S1 G5T3
Figure 3: Rare Plants of Cape Romain NWR
1 As Ipomoea stolonifera 2 As Sagittaria graminea var. weatherbiana
Lowcountry and Savannah Refuge Complexes Floristic Inventories 10 Ernest F. Hollings ACE Basin National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge. Some botanists have made limited collections of specimens. In 1956 Harry Ahles & C. Ritchie Bell probably collected on the refuge along State Road 33 southeast of Yemassee. Other collectors include Daniel Payne (2006), John Nelson and Richard Porcher (2010).
The flora of the refuge consists of 886 taxa, the second-most diverse in this study, but just slightly higher than Waccamaw NWR. Of these 125 (14.1%) are exotic, and 25 of these are listed by SCEPPC.
Four At-risk species were found at ACE Basin NWR in 2016-2017, all new records, and detailed in Bradley (2018). Thirteen additional rare species tracked by SCDNR were found (Table 7, Figure 4, Figure 5, Figure 6). SCDNR had no rare plant occurrence data for the refuge. Surveys were conducted in all management units. In 2018-2019 new populations of the At-risk species Coreopsis integrifolia and Isoetes hyemalis were found and mapped. New additions are indicated with an asterisk (*).
• Coreopsis integrifolia (Chipola dye-flower): A new colony was found in the Upper Combahee Unit in Hampton County, northeast of Yemassee (Figure 4). This population extends along much of Rum Bluff Road, from just above US21/AltUS17, to almost the northeastern property line. The population is scattered on boat sides of the road both on the refuge side and the private property side, and much is under a powerline easement. • Isoetes hyemalis (Wintergreen quillwort): Two new colonies were found. One of these was found in the Upper Combahee Unit in Hampton County, northeast of Yemassee, along the northern property line in the bed of an old road (Figure 4). The other was at Grove Plantation along the eastern property line, ca. 0.35 km north of Fairview Nursery Road (Figure 5). While the map in (Figure 4) shows the population to be outside of the Refuge, it was along the property line.
Table 7: Rare Plant Species of Ernest F. Hollings ACE Basin NWR
Scientific Name Common Name Recorded USFWS SCDNR Global Status Bacopa innominata* Tropical Water-hyssop Yes S1 G3G5 Burmannia biflora Violet burmannia Yes S2 G4G5 Carex amphibola Eastern narrow-leaved Yes SNR G5 sedge Carex basiantha Southern Willdenow's Yes S2 G5 Sedge Carex hyalinolepis Shoreline sedge Yes S2 G4G5 Coreopsis integrifolia Chipola dye-flower Yes At-Risk S1 G1G2 Ilex amelanchier Sarvis holly Yes S3 G4 Isoetes hyemalis Wintergreen quillwort Yes At-Risk S1 G2G3 Macbridea caroliniana Carolina birds-in-a-nest Yes At-Risk S3 G2G3 Peltandra sagittifolia Spoonflower Yes S2 G3G4 Phyla lanceolata* Marsh frogfruit Yes SNR G5 Physostegia leptophylla Tidal marsh obedient-plant Yes SNR G4? Ptilimnium ahlesii Carolina bishopweed Yes At-Risk S1 G1 Quercus austrina* Bluff oak Yes S1 G4?
Lowcountry and Savannah Refuge Complexes Floristic Inventories 11 Sagittaria weatherbiana*1 Weatherby’s Arrowhead Yes S1 G5T3T4 Symphyotrichum elliottii Southern swamp aster Yes S3 G4 Tridens strictus Longspike fluffgrass Yes S1 G5
Figure 4: Rare Plants of Ernest F. Hollings ACE Basin NWR (Upper Combahee Unit)
1 As Sagittaria graminea var. weatherbiana
Lowcountry and Savannah Refuge Complexes Floristic Inventories 12
Figure 5: Rare Plants of Ernest F. Hollings ACE Basin NWR (Edisto Unit)
Figure 6: Rare Plants of Ernest F. Hollings ACE Basin NWR (Bonnie Hall Unit)
Lowcountry and Savannah Refuge Complexes Floristic Inventories 13
Harris Neck National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge. Some botanists have collected small numbers of specimens, including Marie and E.O. Mellinger (1958-1965). The flora had been little studied.
The flora of the refuge consists of 484 taxa. Of these 94 are exotic (19.4%), and 21 of these are listed by GAEPPC.
No At-risk plant species were found at Harris Neck NWR. Four state-tracked species were found, including one addition in the 2018-2019 season (Table 8, Figure 7). The GADNR heritage program database had one tracked species mapped for the refuge, Aeschynomene viscidula. This mapped occurrence was not relocated and may be extirpated, but the species was found in two other locations in the refuge. The new addition is indicated with an asterisk (*).
A native herb, Eupatorium scabridum, was found along Harris Neck Road in a moist swale across from Friendship Church. While not tracked by Georgia DNR it has only been found in the state a few times, including McIntosh County on Sapelo Island, Chatham County, and Evans County. It is probably a hybrid between E. rotundifolium and E. semiserratum. Neither of these species was recorded at the Refuge but should occur nearby. It is considered by some authors to be conspecific with E. rotundifolium.
Two colonies of the exotic grass Paspalum nicorae were found. One was in a lawn at Barbour Landing, and another along the edge of Harris Neck Road. This is apparently the first record of this species growing wild in Georgia. It is a pasture weed in Florida. Desmodium triflorum, an exotic herb, was recorded at the Refuge in 2016 and 2017. As discussed in Bradley (2018) this was the first record of the species in Georgia. Another exotic legume, Macroptilium lathyroides, was found around a culvert on Harris Neck Road. This species has been collected in Georgia only about 7 times, and appears to be increasing in frequency.
Table 8: Rare Plant Species of Harris Neck NWR
Scientific Name Common Name Recorded USFWS GADNR Global Status Aeschynomene viscidula Sticky joint-vetch Yes S1? G5? Andropogon longiberbis Longbeard bluestem Yes S1? G5 Eleocharis montevidensis Sand spikerush Yes S3? G5 Tephrosia chrysophylla* Sprawling Goat's-rue Yes S1 G4G5
Lowcountry and Savannah Refuge Complexes Floristic Inventories 14
Figure 7: Rare Plants of Harris Neck NWR Pinckney Island National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge. Some botanists have collected at the refuge, most notably Daniel Payne (1998-2006) (Payne 2010), but small numbers of specimens were also collected by Bob Peet (1996), Richard Porcher (1996), John Ebinger (1997), Lisa Kelly (1998), and Jim Matthews (2011).
Surveys were conducted throughout the refuge, including Pinckney Island from Last End Point to White Point, as well as on Big Harry Island, Little Harry Island, and Corn Island. No federal species of interest were encountered, nor have any been previously documented on the refuge. Nine state-tracked species were found, seven of these newly reported for the refuge (Table 9, Figure 8). The state-tracked Clematis catesbyana was found previously by R. Porcher in 1996 (2696, CLEMS), was not seen in 2016-2017, but was located in 2018. No new rare species were observed in 2018-2019.
The flora of the refuge consists of 408 taxa. Of these 85 (20.1%) are exotic, and 16 of these are listed by SCEPPC.
Table 9: Rare Plant Species of Pinckney Island NWR
Scientific Name Common Name Recorded USFWS SCDNR Global Status Clematis catesbyana Coastal virgin’s-bower Yes* SNR G4G5
Lowcountry and Savannah Refuge Complexes Floristic Inventories 15 Cyperus distinctus Swamp flatsedge Yes S1 G4 Eupatorium anomalum Anomalous Yes S1? G2G3 eupatorium Muhlenbergia sericea Dune hairgrass Yes S3S4 G5T5? Psilotum nudum Whiskfern Yes S1 G5 Quercus austrina Bluff oak Yes S1 G4? Sageretia minutiflora Small-flowered Yes S3 G4 buckthorn Scutellaria mellichampii Mellichamp’s skullcap Yes SNR NA Tridens chapmanii Chapman’s triodia Yes S1 G5T3
Figure 8: Rare Plants of Pinckney Island NWR
Santee National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge. Some botanists have collected at the refuge, more than at most refuges. Notable collectors include Robert Godfrey (1939), Al Radford and associates (1957-1968), F. McGilvrey with J. Steenis and N. Hotchkiss (1960), and John Logue (1982-1984), Gerald Long & Richard Harvey (1984), John Nelson and associates (1985-2018), and Marvin Brown (2013). Many of the older records from the 1950s are from Dingle Pond. The SCNDR Heritage Program database also has rare plant records for the refuge, representing six species. These records were from between 1960 and 1998.
Lowcountry and Savannah Refuge Complexes Floristic Inventories 16 Surveys were conducted in each of the four management units on the refuge. The interior of Dingle Pond was accessed to some extent by airboat. An airboat was also used to survey the Plantation Islands area.
The flora of the refuge consists of 707 taxa. Of these 146 (20.7%) are exotic, and 32 of these are listed by SCEPPC.
No federal species of interest were encountered, nor have any been previously documented on the refuge. Seven state-tracked species were found, six of these newly reported for the Refuge (Table 10, Figure 9).
Six state tracked species previously found here could not be relocated, all probably because of changes in habitat conditions. Many of these were formerly collected at Dingle Pond or Colclough, including Burmannia biflora, Hypericum adpressum, Lilaeopsis caroliniensis, and Rhexia aristosa. Habitat conditions have changed in these ponds, actually Carolina Bays, because of the impoundment of Lake Marion. They are now much wetter than historically.
One reported rare species, Bacopa innominata, was found in 1960 in the “Five Pines area”, a site unknown to the author but in the Bluff Unit. An attempt to locate the basis of this record, a specimen collected in 1960 by Neil Hotchkiss was formerly at the Patuxent Herbarium, but no Bacopa specimens could be found there by the curator. Other specimens by the collector and associates, from the refuge, are at the Smithsonian Institution (U.S. National Herbarium), but no bacopa specimens are online. The other four were found at the edge of Dingle Pond. Carex decomposita was not observed in 2016-2017, but was found in 2018. New additions are indicated with an asterisk (*).
Table 10: Rare Plant Species of Santee NWR
Scientific Name Common Name Recorded USFWS SCDNR Global Status Bacopa innominata1 Tropical water-hyssop No S1 G3G5 Burmannia biflora* Violet burmannia No S2 G4G5 Carex amphibola* Eastern Narrow-leaved Yes SNR G5 Sedge Carex decomposita Cypress-knee sedge Yes S2 G3G4 Hydrolea corymbosa Skyflower Yes S1 G5 Hypericum adpressum Bog St. John’s-wort No S2 G3 Lilaeopsis carolinensis Carolina lilaeopsis No S2 G3G5 Lysimachia terrestris* Bog loosestrife Yes SNR G5 Oenothera linifolia* Threadleaf sundrops No S1 G5 Rhexia aristosa Awned meadow-beauty No S3 G3G4 Rhynchospora inundata Narrow-fruit horned Yes S2? G4? beaksedge Sagittaria weatherbiana2 Weatherby’s arrowhead Yes S1 G5T3T4 Vallisneria americana* Vallisneria, Water- Yes S1 G5 celery
1 As Bacopa cyclophylla 2 As Sagittaria graminea var. weatherbiana
Lowcountry and Savannah Refuge Complexes Floristic Inventories 17
Figure 9: Rare Plants of Santee NWR
Savannah National Wildlife Refuge The Savannah NWR has more historical floristic data than other refuges in this study. This is mainly due to a floristic inventory of the refuge done by Marie and E.O. Mellinger (1960), who collected extensively in the refuge. Their list was exhaustive, based on extensive fieldwork over years from 1957 to 1966 (Marie continued to collect after its publication). However, the Refuge boundaries differed in 1960 and was much smaller. At the time it covered 12,689 acres, mainly the rice impoundments and areas eastward, and Isla, Argyle, and Onslow Islands. It also included a small area east of US17 that included upland pine forest and is no longer part of the refuge. This small area contained plant species not now known from the Refuge because of the unique habitat. An attempt has been made to exclude those species from the 2019 inventory.
Other botanists have collected sporadically at the refuge since then. Notable among these include Don Eyles (1939-1940), G.R. Swank (1959-1960), Neil Hotchkiss (1960), John Bozeman (1966), Ted Bradley (1966), Al Radford (1968-1974), Steven Leonard (1968-1969), Alwyn Gentry (1985), and John Nelson (2010-2019). SCDNR and GADNR also have element occurrence data for the refuge.
Surveys were conducted nearly throughout the refuge. A focus was placed on upland habitats within and at the edge of the floodplain of the Savannah River, accessed mainly by boat, and in freshwater tidal marshes.
Lowcountry and Savannah Refuge Complexes Floristic Inventories 18 The flora of the refuge consists of 1100 taxa. This is the highest species richness of the refuges in this study, and higher than that at Carolina Sandhills NWR (Bradley, 2019). Of these 241 (21.9%) are exotic, and 49 these are listed by GAEPPC or SCEPPC.
One At-risk species was found in the refuge, Ptilimnium ahlesii. This species is treated in detail in Bradley (2018). In 2018-2019 one new population was mapped. This population was found on the southeastern portion of the refuge behind the Barrow’s House, along the edge of an upland tree island in a freshwater tidal marsh/rice impoundment.
Nineteen species tracked by either SCDNR or GADNR were found in the state where tracked (Table 11, Figure 10). Five new rare species were found and mapped in 218-2019. New additions are indicated with an asterisk (*). In addition, 18 species tracked by either SCDNR (15) or GADNR (2) were found in the state where tracked are known from historical records, mainly documented by Marie and E.O. Mellinger.
Table 11: Rare Plant Species of Savannah NWR
Scientific Name Common Name Recorded? USFWS Rank Global Status Where Found Acorus calamus1 European calamus No GA(S1S2) G5 Aristida beyrichiana Southern wiregrass No SC(SNR) G5? Bacopa innominata2 Tropical water-hyssop No SC(S1) S1 Carex amphibola Eastern narrow-leaved No SC(SNR) G5 Sedge Carex basiantha* Southern willdenow's Yes SC (S2) G5 Sedge Carex calcifugens* Calcium-fleeing Sedge Yes GA (S2?) G3 Carex corrugata Prune-fruited sedge Yes GA(S2?) G5? Carex dasycarpa Velvet sedge Yes GA(S3) G4? Carex hyalinolepis Shoreline sedge No SC (S2) G4G5 Collinsonia punctata Florida horsebalm Yes SC(S1) G3G4 Cuscuta indecora Bigseed alfalfa dodder No SC(SNR) G5 Epidendrum magnoliae3 Green-fly orchid No SC(S3?) G4 Galactia elliottii Elliott's milkpea No SC(S1) G5 Gelsemium rankinii Swamp jessamine No SC(SNR) G5 Habenaria quinqueseta Long-horned habenaria No SC(S1) G4G5 Halesia diptera Common two-wing Yes SC(S1) G5 silverbell Ilex amelanchier Sarvis holly Yes GA(S2) G4 Lilaeopsis chinensis* Marsh lilaeopsis Yes GA(S2?) G5 Listera australis Southern twayblade No SC(S1) G4 Orobanche uniflora One-flowered No SC(S2) G5 Broomrape Persicaria arifolia* Halberd-leaf tearthumb Yes GA (S1) G5 Phyla lanceolata Marsh frogfruit No SC(SNR) G5
1 As Acorus americanus 2 As Bacopa cyclophylla 3 As Epidendrum conopseum
Lowcountry and Savannah Refuge Complexes Floristic Inventories 19 Physostegia leptophylla Tidal marsh obedient- Yes SC(SNR); G4? plant GA(S2S3) Platanthera integra Golden fringeless No SC(S1) G3G4 Orchid Ptilimnium ahlesii Carolina bishopweed Yes At-risk SC(S1); G1 GA(S1) Quercus austrina Bluff oak Yes SC(S1); G4? GA(S3?) Rhapidophyllum hystrix Needle palm Yes SC(S1) G4 Rhexia cubensis West Indies meadow- No SC(S1) G4G5 beauty Rorippa sessiliflora Stalkless marshcress No SC(SNR) G5 Sagittaria Weatherby’s arrowhead Yes SC (S1) G4G5T4 weatherbiana1* Scutellaria mellichampii Mellichamp’s skullcap Yes SC (SNR) GNR GA(S2?) Sideroxylon alachuense Alachua bully Yes G1(S1) G1 Spermacoce glabra Smooth buttonweed No GA(S2?) G4G5 Symphyotrichum elliottii Southern swamp aster Yes SC(S3) G4 Symphyotrichum laeve Smooth blue aster No SC(SNR) G5 Thalia dealbata Powdery thalia Yes SC(S2) G4 Verbesina walteri Walter’s wingstem Yes GA(S1?) G4
1 As Sagittaria graminea var. weatherbiana
Lowcountry and Savannah Refuge Complexes Floristic Inventories 20
Figure 10: Rare plants of Savannah NWR
Lowcountry and Savannah Refuge Complexes Floristic Inventories 21 Tybee National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge, and no botanist had ever visited. Surveys were conducted on the easternmost portions of the refuge on the oldest fill area, and in portions of the newer, more active fill areas. This Refuge was not included in Bradley (2018), and visits were made only in 2019.
The flora of the refuge consists of 173 taxa. Of these 50 (28.9%) are exotic, and 11 of these are listed by SCEPPC. This refuge has the highest percentage of exotic plant species in its flora than in any other refuge in the study. One species tracked by SCDNR was found (Table 12, Figure 11). This, Ipomoea imperati, was on low beaches near the mount of the Savannah River. The flora here almost entirely artificial. It is located on the eastern end of Jones Island, which was historically tidal marsh dominated by dense Spartina alterniflora, at the mouth of the Savannah River. Uplands were created in this marsh by depositing dredge material from the Savannah River, and material is still deposited there continuously. The oldest fill area is at the east end of the refuge. The vegetation there has formed unique and botanically interesting grasslands, interspersed by lower swales dominated by hardwoods (native and exotic). The more westward portions of the refuge are undergoing regular fill deposition inside the boundaries of levees. The flora here is extremely dynamic. Overall, the refuge is a confounding mix of native weedy species and exotics. This refuge has the highest percentage of exotic species of any of the study refuges, with 28% of the taxa being introduced. Many of the exotic species are very rare in the state, and some are newly recorded. Examples include Fumaria vaillantii (new, and also found in this study at Savannah NWR), Parietaria judaica (2nd collection), and Sesbania drummondii (4th collection).
Table 12: Rare Plant Species of Tybee NWR
Scientific Name Common Name Recorded USFWS SCDNR Global Status Beach morning-glory Ipomoea imperati1 Yes SNR G5?
Figure 11: Rare plants of Tybee NWR
1 As Ipomoea stolonifera
Lowcountry and Savannah Refuge Complexes Floristic Inventories 22 Waccamaw National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge. Very little botanical activity has been conducted in the refuge outside of Sandy Island. A few specimens have been collected by Al Radford (1957), Doug Rayner (1986), and John Nelson (1998 and 2012). Much of this activity was along US701 at the Pee Dee River. The flora of Sandy Island has been well studied and is detailed by Nelson (2006).
Surveys were conducted nearly throughout the refuge. Sandy Island was not surveyed because of previous rare plant mapping and floristic inventory (Nelson 2006). A focus was placed on un- surveyed portions of the refuge. Survey efforts were mainly concentrated along waterways accessed by boat, especially the Pee Dee and Waccamaw Rivers and smaller waterways west and south of Sandy Island. Land based surveys were conducted where access permitted, particularly at the Cox Ferry, the Normandy Tract, and at Jackson Bluff, and at boat landings. The flora of upland portions of Sandy Island are not included in this report and associated database.
The flora of the refuge consists of 849 taxa. Of these 128 (15.1%) are exotic, and 29 of these are listed by SCEPPC.
Nine tracked species were added to the list in 2018-2019. Most of these were found in the Cox Ferry area, associated with a wet powerline easement and a xeric longleaf pine habitat that were not surveyed in 2016-2017. Two of these eleven were found in 2016-2017, but have only recently been tracked by SCDNR (Gelsemium rankinii and Oenothera riparia).
Two Federal At-risk species were found at Waccamaw NWR. One of these, Ptilimnium ahlesii, was a new detection. Nuphar sagittifolia, a species already known from the refuge, was mapped. These species are detailed in Bradley (2018).
Twenty four species tracked by SCDNR were found (Table 13, Figure 12, Figure 13, Figure 14). New additions since Bradley (20018) are indicated with an asterisk (*). One SCDNR tracked species has been found in the refuge, but was not observed during this study, Sabatia kennedyana. The rare mint Stachys tenuifolia was not seen in 2016-2017. There were two documented populations in the Refuge, one on the edge of Sandy Island, and one on the Bridge Tract just north of US701 on the west bank of the Pee Dee River. Surveys of these locations in 2019 were unsuccessful. The population at US701 may have been destroyed by bridge construction or powerline maintenance. The habitat was intact on Sandy Island and it could still be found there. John Nelson (personal communication, 2019) notes that populations of this species are usually ephemeral. A new population of S. tenuifolia was found in August 2019 at Yauhanna Landing on the east side of the Pee Dee River, along the edge of the filled parking lot. By September 2019 this population had been bulldozed and may have been lost.
Oenothera riparia was added to the SCDNR Heritage Programs list of tracked species in 2019. Because it was not tracked during the majority of field work populations mostly were not mapped. The species is frequent along edges of tidal swamp forests, especially in the vicinity of Sandy Island, including the banks of the Waccamaw and Pee Dee Rivers, Bull, Little Bull, Guendalose, and Thorofare creeks. Colonies tend to have only a few plants because mainly occur in small microhabitats, such as old decaying stumps. In South Carolina the species is mainly
Lowcountry and Savannah Refuge Complexes Floristic Inventories 23 limited to the area of the Waccamaw NWR, with another apparently smaller occurrence on the Edisto River in Colleton and Charleston counties. It is also very rare in the rest of its range in coastal North Carolina and Virginia.
A list of rare plant species that have been recorded in the refuge only on Sandy Island is included below ( Table 14). This list has been generated from Nelson (2006), the SCDNR Heritage Trust Program database, and specimen data on the SERNEC portal. The list includes 11 species tracked by SCDNR. No Federally-listed or At-risk species have been found there.
Table 13: Rare Plant Species of Waccamaw NWR, excluding Sandy Island
Scientific Name Common Name Recorded USFWS SCDNR Global Status Amphicarpum Pinebarrens Yes SNR G4 amphicarpon1* Peanut-grass Aristida condensata* Big Three-awn Yes S2 G4?
Carex amphibola Eastern narrow- Yes SNR G5 leaved sedge Carex cherokeensis* Cherokee Sedge Yes S2 G4G5 Carex crus-corvi Crowfoot sedge Yes S2 G5 Carex elliottii Elliott’s sedge Yes S1 G4? Epidendrum magnoliae Green-fly orchid Yes S3? G4 Gelsemium rankinii Swamp Jessamine SNR Hymenocallis pygmaea Pygmy spiderlily Yes SNR G1G2? Ilex amelanchier Sarvis holly Yes S3 G4 Juncus pelocarpus2* Brown-fruited Yes S2 G4G5 Rush Lachnocaulon minus* Brown Bogbutton Yes S1 G3G4 Nuphar sagittifolia Narrowleaf Yes At-Risk S2 G5T2 pondlily Oenothera riparia* Riverbank Yes SNR G2G3 Evening-primrose Paronychia fastigiata Common Forked Yes SNR G5T5 var. fastigiata* Whitlow-wort Physostegia leptophylla Tidal marsh Yes SNR G4? obedient-plant Pilea fontana Blackfruit Yes SNR G5 clearweed Ptilimnium ahlesii Carolina Yes At-Risk S1 G1 bishopweed Sabatia kennedyana Plymouth gentian No S2 G3? Sagittaria weatherbiana3 Weatherby’s Yes S1 G5T3T4 arrowhead Stachys tenuifolia Smooth hedge- Yes* S1 G5 nettle Symphyotrichum elliottii Southern swamp Yes S3 G4 aster
1 As Amphicarpum purshii 2 As Juncus abortivus 3 As Sagittaria graminea var. weatherbiana
Lowcountry and Savannah Refuge Complexes Floristic Inventories 24 Syngonanthus Yellow Hatpins Yes S2 G5 flavidulus* Xyris flabelliformis* Savanna Yellow- Yes S1 G4 eyed Grass
Table 14: Rare Plant Species Unique to Sandy Island within Waccamaw NWR
Scientific Name Common Name SCDNR Global Status Ceratiola ericoides Florida rosemary S1 G4 Cladium mariscoides Twig-rush S1 G5 Cyperus lecontei Leconte’s flatsedge S1 G4? Eleocharis robbinsii Robbins’s spikerush S2 G4G5 Eleocharis vivipara Viviparous spikerush S1 G5 Lachnocaulon beyrichianum Southern bigbutton S2 G4 Litsea aestivalis Pondspice S3 G3? Pityopsis pinifolia Sandhill goldenaster S2 G4 Narrow-fruit horned G4? Rhynchospora inundata beaksedge S2? Sagittaria isoetiformis Quillwort arrowhead S3 G4? Xyris elliottii Elliott’s yellow-eyed G4 grass S2
Lowcountry and Savannah Refuge Complexes Floristic Inventories 25
Figure 12: Rare Plants of Waccamaw NWR
Lowcountry and Savannah Refuge Complexes Floristic Inventories 26
Figure 13: Rare Plants of Waccamaw NWR (Yauhanna area)
Figure 14: Rare Plants of Waccamaw NWR (Cox Ferry area)
Lowcountry and Savannah Refuge Complexes Floristic Inventories 27 Wassaw National Wildlife Refuge No floristic inventory has ever been compiled for the refuge, and very little botanical activity has been conducted there. About 12 herbarium specimens have been collected and available on sernercportal.org, these by collected J. H. Miller and Bassett Maguire (1928-29), G.R. Swank (1961), Ivan Tomkins (1961), Marie Mellinger (1961), Lee Clermont (1961), A. Salter II (1964), and “Rahn” (1970).
This refuge was not included in Bradley (2018), but one visit was made in 2016. All other visits were made in 2018-2019. On the refuge 270 species have been recorded. Of these 29 (10.7%) are exotic, and six are listed by Georgia EPPC. One species found was new to Georgia, Parapholis incurva. Another exotic grass, Polypogon maritimus, has apparently only been collected three other times in Georgia. These were on Tybee Island in 1901, Sapelo Island in 1956, and Cockspur Island in 1998. Both of these species were found on the refuge at and around the campground and maintenance yard.
Two species tracked by GADNR were found (Table 15, Figure 15).
Table 15: Rare Plant Species of Wassaw NWR
Scientific Name Common Name GADNR Global Status Andropogon longiberbis Longbeard-blustem S1? G5 Eleocharis montevidensis Sand spikerush S3? G5
Figure 15: Rare Plants of Wassaw NWR
Lowcountry and Savannah Refuge Complexes Floristic Inventories 28
Wolf Island National Wildlife Refuge No floristic inventory has ever been compiled for the Refuge, and no botanist had ever collected specimens there.
The small size of the refuge, and in particular the very limited uplands, cause this to have the lowest species richness in this study. The refuge is dominated by tidal marsh dominated by Spartina alterniflora. A narrow beach forms the majority of the uplands. A slightly higher area along the refuge’s southern edge contains shrublands, and this was formerly the site of historic lighthouses. Dredge spoil deposits along the west edge of the refuge are dominated by a low- diversity assemblage of native hardwoods, cabbage palm, and loblolly pine.
Seventy-five (75) species were found and 3 (4.0%) of these are exotics. This is the lowest exotic species count and percentage across all of the refuges in this study. One of these exotics is listed by GA-EPPC, Tamarix gallica, as Cat. 2. The exotic grass Phragmites australis was not observed, but could be found in the refuge, particularly in dredge spoil mounds along the western edge of the refuge. Several of these were searched and the species was not seen, but it does occur on newer spoil deposits immediately west of the refuge.
One rare plant species was found, Forestiera segregata (Table 16, Figure 16). This state-tracked shrub was rare on the extreme southern edge of the island in the vicinity of the former lighthouse. This area had a slightly higher species richness than dunes on the rest of the island.
Table 16: Rare Plant Species of Wolf Island NWR
Scientific Name Common Name GADNR Global Status Forestiera segregata Florida-privet S2 G4
Figure 16: Rare Plants of Wolf Island NWR
Lowcountry and Savannah Refuge Complexes Floristic Inventories 29 DISCUSSION This study, continued since 2016 (Bradley 2018) resulted in the discovery of five Federal At-risk species on three refuges. In general, meta-populations of these species in these refuges are secure in the short term. However, they all face long-term threats. Threats to these At-risk species overlap with those of regionally rare plant species that occur on all seven refuges. With the exception of Santee NWR because of its inland location, all refuges face problems associated with sea level rise. Rare plant species which occupy freshwater tidal habitats, including the At- risk Nuphar sagittifolia and Ptilimnium ahlesii will be particularly sensitive to rising water levels and saltwater intrusion. Regional changes to hydrology could have similar effects, including harbor dredging, river dredging or channel modifications, dam construction, or regional pressure on freshwater aquifers for human and industrial consumption. Sea level rise is also a threat to overall botanical diversity in refuges. On sea islands, such as at Blackbeard Island, Wassaw, and Cape Romain, interdunal freshwater ponds and marshes are being lost. These habitats often harbor species not found elsewhere on these islands, and single storm events which breach dunes and flood this ecosystem result in losses of native species from these islands.
All rare plant species face pressures from invasive organisms. Invasive pest plants can alter habitat structures and functions, displacing rare species. The most problematic invasive plant species to rare plants on the study refuges include Eichhornia crassipes, Ligustrum sinense, Microstegium vimineum, Murdannia keisak, Myriophyllum aquaticum, Panicum repens, Phragmites australis, Pistia stratiotes, Sesbania punicea, and Triadica sebifera. These botanical surveys also revealed new range expansions of exotic plant species. In Georgia, Wassaw and Harris Neck contained state records, including Desmodium triflorum, Parapholis incurva, and Paspalum nicorae. The latter two, both grasses, could become pests in the state. In South Carolina state records were found at Tybee, Cape Romain, and Savannah, including Cyperus lanceolatus, Fumaria vaillantii, and Mecardonia procumbens. The exotic sedge Cyperus alopecuroides is a new introduction in South Carolina (2016) and was found to be frequent within and adjacent to the refuge and will likely become a problematic weed in the state. In 2019 the exotic aquatic fern Salvinia minima was found in a freshwater tidal creek in Waccamaw NWR, representing a new northward range expansion.
Wild hog populations pose threats to all rare plants except aquatic species. Direct impacts of wild hog rooting were observed on populations of Coreopsis integrifolia, Isoetes hyemalis, and Macbridea caroliniana.
Prescribed burning is a critical management too in many ecosystems of the coastal plain, including many in these refuges, and should be used as a tool to maintain populations of rare plant species. The At-Risk species detected in this study were all found in habitats where regular burns are not necessary. While freshwater tidal marshes, habitat for Ptilimnium ahlesii, may burn on occasion, the role of fire is poorly understood, and may primarily occur where immediately adjacent to pyric ecosystems such as pine savannas, but otherwise rarely burn (Schafale and Weakley, 1990). The other At-risk species found in refuges occupy forested wetlands, also a habitat that does not rely on fires, although they probably burned into their periphery and may have historically been important for ecotonal species such as Coreopsis integrifolia in some locations (McMillan et al. 2002). Several regionally rare species, however, were found in pyric ecosystems, such as Burmannia biflora and Eupatorium anomalum, in longleaf pine savannah
Lowcountry and Savannah Refuge Complexes Floristic Inventories 30 and a coastal pine savanna. Such habitats should be burned regularly to maintain habitat for these species.
Presence of rare plant species, particularly Federal At-risk and those ranked as rare by state heritage programs, should be factored into long-term management planning for each refuge. Vegetation management activities including mowing, logging, prescribed burning, and water management should ideally take into consideration impacts on rare plants. The discovery of populations of rare species populations on each refuge indicates that past management actions have been favorable to these species. Ongoing management should take into consideration flowering and fruiting times, for examples, in planning activities such as mowing or brush hogging to ensure annual or periodic seed set and dispersal.
Refuges • Blackbeard Island NWR No At-risk species were found in the refuge. Four state tracked rare species were found. The attractive flowering shrub Hibiscus grandiflorus is common along the east side of Toar Pond. The refuge is close to its northern range limit. On other Georgia sea islands, such as Saint Catherines Island, it is severely threatened by sea level rise causing losses marsh. Georgia DNR reports only 6 locations for this in the state, all from the western edge of the state. Another record, not in the DNR database is the only coastal record seen. This is a specimen from Onslow Island in the Savannah NWR. Blackbeard is the second coastal record in Georgia, although it occurs on the South Carolina coast, where also rare. It should be sought in freshwater tidal wetlands in other parts of Georgia, such as the Altamaha and Ogeechee rivers.
• Cape Romain NWR No At-risk species were found in the refuge; one Federally Threatened species, Amaranthus pumilus, formerly occurred in the refuge and reintroduction efforts for it are underway. The lack of At-risk species is due to the lack of suitable habitats, mainly influenced by the geographic position of the refuge. The At-risk species most likely to be found in the refuge is Forestiera godfreyi. This shrub is restricted to coastal shell middens, a habitat that is not well represented in the refuge. The refuge was found to provide habitat for 14 species tracked by SCDNR. These were widely distributed mainly on Bulls Island, across the island, in several habitats. The majority are associated with impounded wetlands, especially along roads, and in wet roadside ditches, but others are associated with dunes and backdune swales, hammocks on upland sand ridges, and one in a bahia grass lawn.
• Ernest F. Hollings ACE Basin NWR Four At-risk species were found, the most species for any refuge, including Coreopsis integrifolia, Isoetes hyemalis, Macbridea caroliniana, and Ptilimnium ahlesii. These were found in the Bonny Hall, Upper Combahee, and Combahee Fields units. P. ahlesii was found to be infrequent in the refuge in freshwater tidal areas of the Bonny Hall and Combahee Fields units. Populations were mainly on the Combahee River, but one was along the edge of SC-33. The other three species were found in the Bonny Hall Unit, both in bottomland swamp forest and in shallow roadside swales next to management roads. In
Lowcountry and Savannah Refuge Complexes Floristic Inventories 31 2018 I. hyemalis was also found at Grove Plantation. Seventeen rare plant species tracked by SCDNR were recorded. These were found, additionally, on the Grove Plantation, Jehossee Island, and Yemassee South units. One plant species new to South Carolina was found in the Grove Plantation Unit, Baby jump-up (Mecardonia procumbens), likely an accidental introduction. An upland bluff on the Upper Combahee Unit has a population of an Oxalis that may represent an undescribed species. It is under study by Richard Carter (Valdosta State University) and is informally called Oxalis ‘asynchrona’. This purple flowered species is similar to O. violacea which flowers in spring when leaves are present. O. ‘asynchona’ flowers in the fall when leaves are absent.
• Harris Neck NWR No At-risk species were found in the refuge. Four species tracked by GADNR were found. Three of these tracked species, Aeschynomene viscidula, Andropogon longiberbis, and Tephrosia chrysophylla were associated with areas that were logged due to a bark beetle infestation and die off. These upland areas are now generally weedy, but with a higher native graminoid and herb diversity and density than probably existed previously because of the now open canopy and exposed soil. A. viscidula had previously been found on the refuge, but was on a road edge, also a sunny, open habitat. Maintenance of open canopy areas will be important for these species. In 2018 the rare herb Tephrosia chrysophylla was found. This is a very rare species in Georgia, known from only about 6 localities. Eleocharis montevidensis, including Goose Pond and Snipe Pond.
• Pinckney Island NWR No At-risk species were found in the refuge. The lack of At-risk species is due to the lack of suitable habitats, mainly influenced by the geographic position of the refuge. The At- risk species most likely to be found in the refuge is Forestiera godfreyi. This shrub is restricted to coastal shell middens, a habitat that is not well developed in the refuge, although some shell deposits do occur there, e.g. on Dick Pond Point and to a lesser degree on Last End Point. These shell areas do not have the same elevation profile as other known locations for the species in the state. The refuge does provide habitat for nine species tracked by SCDNR. These species were found to be widely distributed across Pinckney Island in several habitats, including shell deposits, coastal grassland, low coastal hammocks, and disturbed wetlands. As discussed in Bradley (2018) Rhynchosia minima was first found in South Carolina at the refuge, and is likely native there. Another herb, the exotic Ranunculus platensis, was found in 2018 in the powerline easement on the south side of US278, east of the boat landing. This species has only been found two other times in the state, in 2012 in Lee County and 2018 in Orangeburg County.
• Santee NWR No At-risk species were found in the refuge. The lack of At-risk species is due to the lack of suitable habitats. This is the only inland refuge in the project, and all habitats here are heavily impacted by the creation of Lake Marion and in management of habitats for waterfowl. Several At-risk species are within the range of the refuge and could have occurred there before the lake was created including Lobelia boykinii, Tiedmannia canbyi, Macbridea caroliniana, and Schwalbea americana. Seven species tracked by
Lowcountry and Savannah Refuge Complexes Floristic Inventories 32 SCDNR were found. Five rare plant species previously known from the refuge were not relocated, probably due to changes in habitat conditions over the period of several decades. The rare plant species that were found were mainly associated with wetlands created for waterfowl management. One of these, Lysimachia terrestris was added to the SCDNR tracked species list in 2019. The colony at the refuge is one of only two populations in South Carolina know to the author, the other at Carolina Sandhills National Wildlife Refuge.
• Savannah NWR One At-risk species was found in the refuge, Ptilimnium ahlesii. Prior to this study it was known in the refuge from a single colony in Georgia. During the study a total of 10 new colonies were found in 2017 and 1 in 2018, including one off-refuge. All populations were found in freshwater tidal marshes, especially on slightly elevated berms just above high tide level at edges of tidal creeks, as well as along edges of artificial levees/tidal marshes.
Eighteen other rare plant species tracked by SCDNR or GADNR were recorded. These were found across the refuge, in freshwater tidal marshes, rice impoundments, and upland hardwood forests.
A floristic inventory of the refuge was compiled by E.O. and Marie B. Mellinger (1960), based on observation and collections made from 1957 to 1960. They report 18 rare species tracked in either South Carolina or Georgia that were not found during the 2016- 2019 study. Herbarium specimens confirm the identify of many of these and provide locality data (e.g. which state) to supplement that given in their report. A number of other rare species records could not be corroborated with specimen data available online, or likely occurred outside of the current refuge boundary. Regardless, the number of rare species that they did observe which were not observed recently is noteworthy. Some of these were probably just overlooked in 2016-2019, e.g. Listera australis is both inconspicuous and flowers in habitats that were surveyed in 2017, but after its very early (mainly February-April) flowering period. Other species are probably absent because of long-term vegetation changes, e.g. due to sea level rise. Another large group of species occurred in flatwoods habitats along US17a. These have been lost due to a lack of periodic fires.
Of particular interest in this refuge are upland hardwood forests. These have formed in two conditions; either as bluffs along the edge of the Savannah River floodplain, or as discrete islands within the floodplain that are surrounded by tidal swamp forests. These islands are referred to as South Atlantic Swamp Islands (USNVC 2017), or “Spruce Pine - Live Oak - Pignut Hickory / American Hornbeam / Saw Palmetto Swamp Forest”. These islands are found both in the south end of the refuge (Pools 14-18), and then north of I-95. In management pools the islands have been degraded due to hydrological changes, human settlement, and invasive pest plants and are of lower quality, but still contain populations of rare plants (Halesia diptera and Quercus austrina). North of I-95 the islands are of much higher quality, occupy more area, and have higher elevations of up to about 26 m. These northern islands have a diverse understory flora with many rare
Lowcountry and Savannah Refuge Complexes Floristic Inventories 33 and otherwise interesting plant species. These islands (and floodplain bluffs) contain dense growths of needle palm. Reaching its northern range in Beaufort County, SC, the refuge probably contains more of this species than all other populations in the state combined. Other rare species include, Carex dasycarpa, Collinsonia punctata (bluff only), Scutellaria mellichampii, Sideroxylon alachuense, and Verbesina walteri (bluffs only). Aside from these state ranked species, unusual species not normally found in the coastal plain include Carex basiantha, Carex cumberlandensis, and Tradescantia subaspera.
A number of exotic species were found that represent new range expansions and state records. Indigofera spicata is at the bar gate on Onslow Island, and is the fifth time found in the Georgia. What is apparently Amaranthus tuberculatus was found in a dredge pond on Onslow. This species has only been collected two other times in Georgia. Unusual species from South Carolina include Cyperus alopecuroides, Melinis repens, Mitracapus hirtus, and Scoparia dulcis.
• Tybee NWR Only one rare plant species was found on the refuge, Ipomoea imperati, a rare to uncommon mainly tropical vine reaching its northern range limit in the Carolinas. It was found only on very low dunes fronting the Savannah River. This population will most likely be lost due to sea level rise if beaches do not accrete here. If biologists make other visits here, they should search for Vachellia farnesiana. This rare tropical shrub reaches its northern range limit directly across the Savannah River at Fort Pulaski National Monument on Cockspur Island. It was not seen in this study, but could be encountered on the oldest fill deposits at the eastern end of the refuge. The dredge fill deposits at Tybee host large populations of exotic invasive species. Phragmites australis forms dense monocultures in wet areas. One species was found represented the first report for South Carolina, Fumaria vaillantii, a European herb (it was also found in Savannah NWR). If possible, management of exotics here should be considered to prevent populations from expanding to nearby natural areas, including those in the Savannah NWR, Fort Pulaski National Monument, and Wassaw NWR.
• Waccamaw NWR Two At-risk species were found in the refuge, Ptilimnium ahlesii and Nuphar sagittifolia. P. ahlesii is rare in the refuge and is restricted to its southern portions in freshwater tidal marshes. N. sagittifolia is ubiquitous. It reaches its greatest abundance in the southern freshwater tidal marshes, but is still common northward in waterways through freshwater tidal swamps. The refuge (excluding Sandy Island) was found to provide habitat for 25 species tracked by SCDNR. These species were widely distributed and occurred in several habitats. The majority (11) were associated with bottomland forests. Seven were associated with pine-dominate habitats at Cox Ferry Recreation Area. Four species were associated with freshwater tidal marshes, two with upland forests on the Normandy Tract.
The eastern portions of the Cox Ferry Lake Recreation area were not surveyed until 2018. The area consists of disturbed pond pine flatwoods and fire suppressed longleaf pine sandhill. A utility easement cuts across the pone pine flatwoods. These flatwoods,
Lowcountry and Savannah Refuge Complexes Floristic Inventories 34 particularly within the utility line, harbor several rare plant species, including Amphicarpum amphicarpon, Carex elliottii, Juncus pelocarpus, Lachnocaulon minus, Syngonanthus flavidulus, and Xyris flabelliformis. The longleaf pine sandhill at the extreme eastern edge of the refuge had the rare grass Aristida condensata. Restoration of these pine-dominated habitats should be continued. Prescribed fire would increase habitat quality and benefit all of the rare species found there.
A diverse seepage slope exists adjacent to the Webb Tract, mainly on private property. This seepage community has formed on a west facing slope between the river floodplain and a xeric longleaf pine sandhills. Within the utility easement, the slope is a diverse wetland with rare plant species, including Carex elliottii, Syngonanthus flavidulus, and Xyris flabelliformis. At the refuge boundary the slope becomes dominated by dense hardwoods. Clearing of hardwoods within the refuge should be considered to expand the extent of the ecosystem, and rare plant species, into the refuge.
• Wassaw NWR No At-risk species were found in the refuge. Two state tracked species were found. Andropogon longiberbis was associated with an inland dune in a coastal grassland. Eleocharis montevidensis was found in several locations, associated with interdunal marshes. The diversity of this island is threatened by the incursion of sea water, associated with sea level rise, into interdunal ponds and marshes. Several have been lost. These wetlands are also severely threatened by the exotic invasive tree Triadica sebifera. One species found was new to Georgia, the exotic grass Parapholis incurva. Another exotic grass, Polypogon maritimus, has apparently only been collected three other times in Georgia. These were on Tybee Island in 1901, Sapelo Island in 1956, and Cockspur Island in 1998. Both of these species were found on the refuge at and around the campground and maintenance yard.
• Wolf Island NWR This refuge had the lowest diversity in the study. This was expected because of its small size and little upland habitat. One rare plant species, the shrub Forestiera segregata was found. This was along the south edge of Wolf Island amongst the remains of the former lighthouses. Only one visit was made to this refuge. Additional visits would result in a higher species richness, but still very low. Visits should be made to additional dredge spoil mounds on Wolf Island, and to uplands on Egg Island.
Lowcountry and Savannah Refuge Complexes Floristic Inventories 35 ACKNOWLEDGMENTS I thank M. Forbes Boyle and the USFWS for the opportunity to do this project, all refuge managers and biologists for their help, including their expert knowledge of refuges, with access, and field help, including Kimberly Hayes (Harris Neck), Chuck Hayes, Wayne Harris, and Russell Webb (Savannah complex), Mark Purcell and Jason Craig (ACE Basin), Marcie Kapsch and Garret Wilkerson (Santee), Sarah Dawsey and Jean Ruble (Cape Romain), Craig Sasser and Jason Hunnicutt (Waccamaw), Tim Fotinos, and Joan Collier. I also thank other colleagues for help with data, sharing their knowledge, and field assistance including April Punsalan (USFWS), Tom Patrick (GADNR), Jacob Thompson (GADNR), John Nelson (University of South Carolina), Herrick Brown (University of South Carolina), Bert Pittman (SCDNR), Kathy Boyle (SCDNR), Trapper Fowler (SCDNR), and Linda Chafin (University of Georgia), Amy Jenkins (Florida Natural Areas Inventory). This project was funded through the U.S. Fish and Wildlife Service Region 4, Inventory and Monitoring Branch.
LITERATURE CITED Bradley, K. A. 2018. At-Risk Plant Occurrences on National Wildlife Refuges within the South Carolina Lowcountry and Savannah Complexes. Report submitted to the U.S. Fish & Wildlife Service, Southeast Region Inventory and Monitoring Branch. Bradley, K. A. 2019. At-Risk Plant Occurrences and Floristic Inventory, Carolina Sandhills National Wildlife Refuge. Report submitted to the U.S. Fish & Wildlife Service, Southeast Region Inventory and Monitoring Branch. McMillan, P. D., R. K. Peet, R. D. Porcher, and B. A. Sorrie. 2002. Noteworthy botanical collections from the fire-maintained pineland and wetland communities of the coastal plain of the Carolinas and Georgia, Castanea, 67(1), pp. 61-83. Mellinger, E. O. and M. B. Mellinger. 1960. Plants of the Savannah National Wildlife Refuge. Bureau of Sport Fisheries and Wildlife, Hardeeville, South Carolina. Nelson, J. B. 2006. Sandy Island: Natural Communities, Vegetation, and Disturbance. Unpublished report. Omernik, J. and G. Griffith. 2008. Ecoregions of the United States-Level IV (EPA). Retrieved from http://www.eoearth.org/view/article/152243 (April 8, 2016). Payne, D. C. 2010. A survey of the vascular flora of Beaufort county, South Carolina. Thesis, Clemson University, Clemson, USA. Schafale, M. P. 2012. Guide to the natural communities of North Carolina, fourth approximation. North Carolina Natural Heritage Program, Department of Cultural Resources, Raleigh, NC. Schafale, M. P. and A. S. Weakley. 1990. Guide to the natural communities of North Carolina, third approximation. North Carolina Natural Heritage Program, Department of Cultural Resources, Raleigh, NC. Sorrie, B. A., and A. S. Weakley. 2001. Coastal Plain plant endemics: Phytogeographic patterns. Castanea 66:50-82. Thiers, B. [continuously updated]. Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden's Virtual Herbarium. http://sweetgum.nybg.org/science/ih/. USNVC. 2017. United States National Vegetation Classification Database, V2.01. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. [usnvc.org]
Lowcountry and Savannah Refuge Complexes Floristic Inventories 36 Weakley, A. S. 2015. Flora of the Southern and Mid-Atlantic states. Working draft of 2015. University of North Carolina Herbarium (NCU), Chapel Hill, USA. 1320 pp.
Lowcountry and Savannah Refuge Complexes Floristic Inventories 37 DATA APPENDIX OR SUPPLEMENTAL INFORMATION
An excel file (OccurrenceData2019.xlsx) provides point data collected on or near refuges of all rare plant species. An ESRI shape file is provided for species locations (NewRecordsPoints2019.shp), projection in NAD83/ UTM Zone 17N. An excel spreadsheet is also provided containing all floristic data (Inventories2019.xlsx).
Appendices 1-12 include floristic inventories of each refuge.
The “Occurrence” field includes a categorization of the validity of each taxon record (P=Present, H=Historical, i.e a reliable record but not seen recently, D = Doubtful, F = False).
The “Nativity” field includes a categorization of native status. N = Native to the Refuge, E = Exotic, and C = Exotics in cultivation.
“GADNR” and “SCDNR” represent classification of conservation status by state heritage programs.
“GAEPPC” and “SCEPPC” represent classifications by state Exotic Pest Plant Councils of invasive status of exotic plant species
Lowcountry and Savannah Refuge Complexes Floristic Inventories 38