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A Floristic Study of a Steephead Stream in Northwestern Florida
Courtney R. Holt, George W. Folkerts, and Debbie R. Folkerts

Southeastern Naturalist, Volume 10, Issue 2 (2011): 289–302

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2011 SOUTHEASTERN NATURALIST 10(2):289–302 A Floristic Study of a Steephead Stream in Northwestern Florida Courtney R. Holt1,*, George W. Folkerts2, and Debbie R. Folkerts3 Abstract - Steepheads are unique ravine habitats of the Gulf Coastal Plain; however, the biology of these habitats is relatively unknown. The objectives of this study were to provide a comprehensive list of wetland plant species along a steephead stream in Santa Rosa County, FL and to compare the floristics along the stream. Species richness (S = 102), evenness (J' = 0.86), and diversity (H' = 3.97) were calculated as well as taxonomic richness (G = 67 genera), evenness (GJ' = 0.95), and diversity (GH' = 3.98). Upstream and downstream sections harbored distinct plant communities (Jaccard index [JI] = 13.33%). The high diversity and lack of non-native species illustrates the need for further investigation into steephead habitats. Introduction Steepheads are diverse, under-studied habitats of the southeastern Coastal Plain. First to describe the habitat, Sellards and Gunter (1918) defined steepheads as nearly vertical bluffs that form in deep sandhills from which springs emerge. These steepheads take on an amphitheater-like shape and can be 18 m or more deep. The streams that emerge from the bases of these ravines are listed as a type of seepage stream by the Florida Natural Areas Inventory (FNAI 1990). Steepheads in the Florida Panhandle are commonly found in the deep sands of the Citronelle formation as well as in younger sands south of the Cody Scarp, an ancient shoreline (Enge 1998, Wolfe et al. 1988). Sediments are of Miocene or Pliocene age and are fine- to coarse-grained sand intermixed with gravel (Means 2000, Platt and Schwartz 1990). These sands contain little clay or silt and were uncovered approximately two million years ago following the recession of the Gulf of Mexico (Means 1985). Steepheads are formed as a stream emerges from beneath the ground surface, causing the sand above the emergent point (“head”) to slump. Schumm et al. (1995) referred to the actual water emergence as “spring sapping” rather than seepage erosion because the water discharge is concentrated as specific point sources. It was previously thought that water rapidly percolates through the sand until it reaches a confining layer where it is forced out to form the head of the stream (Sellards and Gunter 1918). However, drilling has revealed that some steepheads lack a hardpan, indicating steepheads can form in homogenous sediments (Schumm et al. 1995). Howard (1990) suggested riverine valleys that form in homogeneous sediments are controlled by the slope of the water table. However, more geologic and hydrologic investigation of steephead formation are needed to fully support this idea. 1806 Sterling Ridge Drive, Augusta, GA 30909. 2Department of Biological Sciences, Auburn University, AL 36849 (now deceased). 3331 Funchess Hall, Department of Biological Sciences, Auburn University, AL 36849. Corresponding author - cholt9@gmail.com. 290 Southeastern Naturalist Vol. 10, No. 2 The erosional processes occurring in steepheads, however, are well understood and documented. The origin point of the steephead migrates further into the sandhill as erosion continues (Schumm et al. 1995, Sharp 1938). Over time, the water carries sand downstream and a U-shaped valley develops. As the springwater removes sand from the base of the slope, the slope becomes undercut. Eventually, the sand above slumps into the emerging spring water and is carried away, beginning the process again, causing the valley to migrate headward (Means 1991). The rate of headward erosion has been estimated to be about 2–5 cm each century (Eglin AFB Steephead Monitoring Plan 2004). Some of the deepest and most well-developed steepheads can be found on Eglin Air Force Base (Santa Rosa, Okaloosa, and Walton counties, FL) and along the Apalachicola River (Liberty County, FL) (Means 1991). Unfortunately, there is no published data regarding average dimensions or numbers of steepheads in the Gulf Coastal Plain. Because steepheads form in porous substrates, water flow is fairly constant. Natural filtration through layers of sand also causes the water to emerge relatively neutral in pH and with few pollutants (Means 1991, Wolfe et al. 1988). There have been few surveys of the vegetation along steephead streams (Chafin et al. 1997, Means 1985). The majority of studies have focused on plant diversity of the steephead slopes (Clewell 1981, Eglin AFB Steephead Monitoring Plan 2004, Enge 1998, Kwit et al. 1998, Wolfe et al. 1988). The upper slopes of the ravines are typically xeric deciduous forest, followed further down the slope by mesic forest, and finally ending with wetland at the base of the ravine. Rare wetland plants such as Drosera intermedia Hayne (Water Sundew), Macranthera flammea (Bartram) Pennnell (Flameflower), Rhododendron austrinum (Small) Rehder (Flame Azalea), Rhynchospora crinipes Gale (Mosquito Beaksedge), Sarracenia leucophylla Raf. (White-top Pitcher Plant), Sarracenia rubra Walt. (Red Pitcher Plant), and Xanthorhiza simplicissima Marsh. (Yellowroot) have been reported from steepheads (Chafin et al. 1997, US Fish and Wildlife Service 2007). This study was initiated due to the lack of comprehensive floristic information from steephead habitats. The objectives were (1) to describe the flora of one steephead wetland (Weaver Creek) from the head of the stream to the foot (its point of entry into Weaver River) and (2) to compare the upstream and downstream wetland habitats of this steephead. Field-Site Description Weaver Creek is located 18.8 km southeast of Milton, FL on Eglin Air Force Base in Santa Rosa County, FL (coordinates: 30°30'27.84"N, 86°54'46.95"W) (Fig. 1). It was selected for the study based on its large size and accessibility. Its location on Eglin Air Force Base affords it a certain amount of protection from development and other human disturbance. It is a steephead stream with multiple points of origin, all of which are found at the bases of sandhills, and is part of the Yellow River drainage. Elevation on top of the ridge at the head of the stream is 33.2 m above sea level (asl). The elevation at the base of the ridge at the head is 2011 C.R. Holt, G.W. Folkerts, and D.R. Folkerts 291 11.3 m asl. At the entry point into Weaver River (the “foot” of the stream), the elevation drops to 0.91 m asl. Total stream length is 6.10 km, and widths range between 2 m at the head to 20 m at the foot. Water depths range from a few centimeters at the head to over 3 m deep near the foot. The approximate area of the wetland is 0.55 km2. Valley width at the head is approximately 300 m. The steep walls at the head of the ravine, which is approximately 20 m wide at the narrowest point, limit the wetland habitat there to primarily the stream itself. Due to topographical and vegetational differences between the upper and lower reaches of Weaver Creek, two separate habitats were defined for this study: “upstream” (originating at the head of the stream and continuing for 3.04 km) and “downstream” (the remainder of the stream until its entry in Weaver River) (Fig. 1). In total, the upstream area of the wetland is approximately 0.13 km2. Due to the steep slope and dense wetland vegetation, the upstream section is more heavily shaded than the downstream portion. Downstream, the channel widens and deepens significantly. At the foot of the stream, the valley is nearly 700 m wide. The majority of wetland species found downstream are located on soil adjacent to the stream rather than in the stream Figure 1. Map of Florida with Santa Rosa County highlighted. Enlarged is a topographic map (10-ft contours) of Weaver Creek with the head and foot of the creek indicated as well as the upstream and downstream sections (USDA 2010). Coordinates at creek origin: 30°30'27.84"N, 86°54'46.95"W. 292 Southeastern Naturalist Vol. 10, No. 2 channel itself. A 180-m wide wetland area characterized by constantly saturated soils and increased light penetration comprises the downstream section of the study site. Total area of the downstream wetland habitat is approximately 0.42 km2. This section of the study site is heavily shaded by the overstory but also contains canopy gaps, allowing for pockets of increased light penetration. According to the Florida Geological Survey (1993), Weaver Creek is situated on two geological formations. The upper ¾ of the stream is on the Citronelle Formation, which is characterized by fine- to coarse-grained sands interspersed with gravel, silt, and clay. The remainder of the study site is characterized by alluvial deposition in the Weaver River floodplain and contains even finer sands in the substrate (Florida Geological Survey 1993). Upstream areas of the study site are alluvial and well-drained, with Lakeland sands occurring on level to sloping (0–30%) terrain (Weeks et al. 1980). Downstream is characterized by an association of Dorovan and Pamlico soils, creating a mucky substrate (saturated year round) that has formed via decomposition of plant material (Weeks et al. 1980). The water is remarkably clear for the entire length of the stream, indicating little impact from sediment runoff. Water temperature of the stream (23 °C) remained fairly constant during the study period and is consistent along its length. The average pH of the water during the study period was 5.6. Methods Plant collections began on 20 August 2006 and were concluded on 18 September 2007. A total of fourteen site visits were made. The entire wetland area was surveyed in order to obtain samples of all vascular species present. The wetland was defined as areas in and along the stream with saturated soil and/or standing water with emergent vegetation. Identification of unknown specimens was accomplished using Godfrey and Wooten (1981). At least one voucher specimen of each species was deposited in the Freeman Herbarium (AUA) at Auburn University, Auburn, AL. Upstream and downstream sections were treated as two distinct habitats. Visually, these two areas are easily discernible based on vegetation, stream width, and relative vegetation density. Species richness, species evenness, and species diversity (the Shannon index) were calculated for each section of the stream and for the stream as a whole. The following formulas were used: species richness (S) = number of species; species evenness (J') = H'/ln(S); and species diversity (H') = -Σ (pi x ln[pi]), where pi = proportion of species i in total species (Ludwig and Reynolds 1988). The Shannon index was chosen for this analysis because it takes into account both species richness and evenness. In order to measure diversity at the generic level, taxonomic richness (G), evenness (GJ') and diversity (GH') were calculated using numbers of genera and counts of species within genera instead of individuals within species. Community similarity between the upstream and downstream sections was determined using the Jaccard index: JI = j/r x 100, where j = number of species found at both locations and r = number of species unique to either location. The Jaccard 2011 C.R. Holt, G.W. Folkerts, and D.R. Folkerts 293 index was chosen for this analysis because it requires only presence-absence data and is not biased by small sample sizes (Ludwig and Reynolds 1988). Relative abundance values were used to assign each species to one of the following categories: rare (0–5 individuals or clones), infrequent (6–30 individuals or clones), occasional (31–100 individuals or clones), frequent (100–500 individuals or clones), or abundant (>500 individuals or clones). Results In the entire wetland region of the Weaver Creek steephead, 102 species were recorded from 67 genera and 46 families (see Appendix). Of these, 10 species are listed in Florida as commercially exploited, threatened, or endangered. No non-native species were found at the study site. The results of species and generic richness, evenness, and diversity analyses are shown in Table 1. There is a distinct difference in floristic composition between upstream and downstream sections. This distinction is best illustrated by the low degree of similarity between the two habitats (Table 1). Floristic differences between upstream and downstream sections are also well illustrated by the numbers of rare or infrequent species found at each site (Table 1). Discussion As a whole, the wetland of Weaver Creek appears to have a high degree of species and generic diversity when compared with other wetland habitats (Bell et al. 2005, Brandt et al. 2003, Grell et al. 2005, Keddy et al. 2006, Morzaria-Luna et al. 2004, Mulhouse et al. 2005, Tyndall et al. 1990). Much of this diversity is due to the presence of two distinct floristic communities (upstream and downstream). Some species were located throughout the study site, but the majority of species were unique to one section. The two sections consist of very different soil type and habitat structure, a fact which helps explain the low degree of floristic similarity between them. Upstream in alluvial soils, the wetland is more heavily shaded due in large part to the slope vegetation. Downstream in mucky soils, the slope is very gradual, resulting in a single overstory layer and decreased shade as compared to upstream. Shade may be the most important factor explaining the diversity of small herbaceous species found exclusively downstream. These Table 1. Species richness (S) (including number of species unique to each section in parentheses), evenness (J'), and diversity (H') of upstream and downstream sections of Weaver Creek and the entire length of the creek are reported. R/I reports the numbers of rare (R) or infrequent (I) species with proportions of total richness in parentheses. Generic richness (G) (with number of genera unique to each site in parentheses), evenness (GJ'), and diversity (GH') of each section of the study site are shown. Community similarity (JI) between upstream and downstream sections is reported in the final column. S J' H' R/I G GJ' GH' JI Upstream 41 (29) 0.88 3.28 9 (22%) 34 (25) 0.97 3.43 13.33% Downstream 73 (61) 0.84 3.61 35 (48%) 43 (34) 0.93 3.49 Entire creek 102 0.86 3.98 44 (43%) 67 0.95 3.98 294 Southeastern Naturalist Vol. 10, No. 2 species, nearly half of which are rare or infrequent at the study site, increase the richness and diversity (both species and generic) of the downstream section. Notably 18 sedges, 5 rushes, 4 pitcher plants, and 5 other carnivorous plant species were found only in the downstream section. However, because the downstream community is dominated by two species (Chamaecyparis thyoides [Atlantic White-cedar] and Taxodium ascendens [Pondcypress]), evenness downstream is slightly less than upstream. Additionally, the area of wetland habitat upstream (0.13 km2) is much smaller than downstream (0.42 km2). Although a larger area does not necessarily indicate greater richness, it may be a contributing factor at Weaver Creek. Furthermore, the greater water depth downstream allows for the growth of floating vegetation islands along the edges of the stream. These islands are dominated by Dulichium arundinaceum (Threeway Sedge), Eleocharis elongata (Slim Spikerush), Eriocaulon decangulare (Tenangle Pipewort), Orontium aquaticum (Goldenclub), and Xyris spp. They are relatively large in size, reaching up to approximately 8–10 m long and 2–3 m wide. Upstream, the minimal water depth and extensive shading seem to prohibit the formation of this additional microhabitat. Each section of the stream is characterized by different dominant species. Near the head of Weaver Creek, the wetland is dominated by Cyrilla racemiflora (Swamp Cyrilla), Ilex coriacea (Large Gallberry), Ilex opaca (American Holly), Illicium floridanum (Florida Anisetree), Itea virginica (Virginia Sweetspire), Lyonia lucida (Fetterbush Lyonia), Magnolia grandiflora (Southern Magnolia), Magnolia virginiana (Sweetbay), Myrica cerifera (Southern Bayberry), and Viburnum nudum (Possumhaw). The foot of the stream is dominated by Chamaecyparis thyoides and Taxodium ascendens. Both sections of the stream contain an abundance of Pinus elliottii (Slash Pine). The low degree of community similarity and difference in vegetation strongly support the delineation of these two distinct habitats of Weaver Creek. A number of notable species found in this study were not mentioned in previous steephead studies. In total, 67% of the vascular plant species found in this study were not noted as being present in steepheads by previous authors (Chafin et al. 1997, Clewell 1981, Eglin AFB Steephead Monitoring Plan 2004, Enge 1998, Entrekin et al. 1999, Kwit et al. 1998, Means 1985, Means 1991, SAIC 2006, US Fish and Wildlife Service 2007, Wolfe et al. 1988). The majority (76%) of these newly reported steephead species reside exclusively in the downstream portion. Many previous authors have focused on slope vegetation and the wetland area near the head of steephead streams (Clewell 1981, Eglin AFB Steephead Monitoring Plan 2004, Enge 1998, Entrekin et al. 1999, Kwit et al. 1998, Wolfe et al. 1988). The results of this study indicate the importance of including downstream sections in steephead studies in order to understand their true value in harboring a diversity of wetland species. Including the vegetation near the foot of the stream adds a new dimension to the floristics of steephead wetlands and accounts for 72% of the overall species richness in this study. 2011 C.R. Holt, G.W. Folkerts, and D.R. Folkerts 295 Weaver Creek has a relatively high degree of species richness, evenness, and diversity when compared to wetlands that are alluvial throughout and in which water levels are not constant. Brandt et al. (2003) found a species richness value of 19 over an area of 0.2 km2 and an evenness of 0.68 (using the Jaccard index) in tree islands of Everglades National Park, FL. Although their study site was smaller than Weaver Creek, the authors determined that the area sampled was sufficiently large to provide an accurate estimate of species richness. In a study of bottomland hardwood-Loblolly Pine forest, 71 vascular plant species were recorded over an area of 9 km2 (Grell et al. 2005). Diversity of this bottomland forest (mean H' = 1.68) was also much lower than that of Weaver Creek (Grell et al. 2005). Other wetland systems that have a hydrologic regime similar to Weaver Creek (constant water level) have comparable species richness values. For instance, southern Louisiana pine savannas (a system known to contain a diverse flora) contained 140 herbaceous species in 1 km2 (Keddy et al. 2006) compared to our study site with 102 species in 0.55 km2. Authors of at least one study of wetlands with fluctuating water levels report greater species richness than was found at Weaver Creek. Kirkman and Sharitz (1994) reported the presence of 105 species in only 0.025 km2 in Carolina bay wetlands in South Carolina. However, other research on Carolina bays has shown a lower species richness and/or diversity compared to Weaver Creek (Mulhouse et al. 2005, Tyndall et al. 1990). Carolina bays exhibit a wide range of hydroperiod among sites, which could account for these differences in diversity (Sharitz 2003). Studies have also shown tidal wetlands to be less species rich than Weaver Creek. Morzaria-Luna et al. (2004) found 13 species in a salt marsh within a study area of 0.54 km2. The intertidal zone of Boston Harbor Islands National Park contained 15 species in an area of approximately 3.66 km2 (Bell et al. 2005). The low species richness of tidal wetlands is most likely due to water-level fluctuation and the relatively small degree of topographic heterogeneity in such habitats (Mitsch and Gosselink 2007). Comparisons in this study were based on a survey of only one steephead wetland. Investigation of a large number of steepheads would likely reveal species not recorded in this study. For instance, close to the head of some steephead streams is an open, marshy area which contains herbaceous species not present at Weaver Creek. The head of Weaver Creek does not contain the large openings necessary for such marshes to develop. As with most habitat types, there is inherent variation in floristic composition among steepheads (despite relatively consistent abiotic factors). Further field surveys of a variety of steepheads would provide a more complete picture of the true floristic diversity of steephead wetlands. Because of the rugged terrain of steephead valleys, they are not directly under development or logging pressure. However, the uplands are quickly becoming degraded. Longleaf Pine formerly dominated the upland habitat, but is being replaced by pine plantations and housing and commercial developments (Florida 296 Southeastern Naturalist Vol. 10, No. 2 Fish and Wildlife Commission 2005). Large-scale disturbance of vegetation can lead to increased run-off, and, in turn, increased stream turbidity (Chafin et al. 1997, Schumm et al. 1995). The Florida Fish and Wildlife Conservation Commission (2004) listed declining water quality as a threat to steepheads. Habitat loss and degradation is a widespread problem for wetlands, and steepheads are no exception. The variety of vascular plant species found at Weaver Creek (all of which are native), and the fact that two distinctive communities comprise this stream system, illustrate well the conservation implications of steephead systems as a whole. With increasing human encroachment on these habitats, it is becoming more critical to focus research efforts on steepheads. Cataloguing the biological diversity of these habitats may ultimately lead to their preservation. Acknowledgments Permission from Eglin Air Force Base was obtained to conduct the study. Thanks to Amanda Stevens and Bill Tate at Eglin Air Force Base for access and assistance with the project. Thank you also to Katie Glynn and Scott Pokswinski who provided endless hours of help in the field. Thanks to Bob Boyd, Bob Lishak, and Jess Stephens for their helpful comments on the manuscript. And last, but by no means least, an immense amount of gratitude is due to Dr. George Folkerts, without whom this study would not have been possible. His passion for field biology was contagious and, along with his immense knowledge of the natural world, was indispensable in the field. He is truly missed. Literature Cited Bell, R., R. Buchsbaum, C. Roman, and M. Chandler. 2005. Inventory of intertidal marine habitats, Boston Harbor Islands National Park area. Northeastern Naturalist 12:169–200. Brandt, L.A., D. Ecker, I.G. Rivera, A. Traut, and F.J. Mazzotti. 2003. Wildlife and vegetation of bayhead islands in the A.R.M. Loxahatchee National Wildlife Refuge. Southeastern Naturalist 2:179–194. Chafin, L., C. Kindell, B. Herring, C. Nordman, J. Jensen, and A. Schotz. 1997. Natural community survey of Eglin Air Force Base, 1993–1996: Final Report. Florida Natural Areas Inventory, Tallahassee, FL. Clewell, A.F. 1981. Natural setting and vegetation of the Florida Panhandle. Prepared for US Army Corps of Engineers, Mobile, Alabama. Contract No. DACW01- 77-C-0104. Eglin Air Force Base (AFB) Steephead monitoring plan. 2004. Jackson Guard, Eglin AFB, Niceville, FL. Enge, K.M. 1998. Herpetofaunal drift-fence survey of steephead ravines in the Apalachicola and Ochlockonee river drainages. Final Performance Report. Florida Game and Freshwater Fish Commission, Tallahassee, FL. Entrekin, S.A., S.W. Golladay, M. Ruhlman, and C. Hedman. 1999. Unique steephead stream segments in southwest Georgia: Invertebrate diversity and biomonitoring. Pp. 295-298, In K. Hatcher (Ed.). Proceedings of the Georgia Water Resources Conference, Athens, GA. Flora of North American Editorial Committee (Eds.). 1993+. Flora of North America North of Mexico. 15+ vols. Flora of North America, New York, NY and Oxford, UK. 2011 C.R. Holt, G.W. Folkerts, and D.R. Folkerts 297 Florida Fish and Wildlife Conservation Commission. 2004. Florida’s wildlife legacy initiative: Florida’s comprehensive wildlife conservation strategy. Tallahassee, FL. Florida Fish and Wildlife Conservation Commission. 2005. Florida’s wildlife legacy initiative: Florida’s comprehensive wildlife conservation strategy. Tallahassee, FL. Florida Geological Survey. 1993. Geologic map of Santa Rosa County. Available online at http://www.dep.state.fl.us/geology/gisdatamaps/county_maps.htm. Florida Department of Environmental Protection. Accessed 25 May 2007. Florida Natural Areas Inventory (FNAI). 1990. Guide to the natural communities of Florida. Available online at http://fnai.org/naturalcommguide.cfm. Florida State University, Tallahassee, FL. Accessed 6 June 2006. Godfrey, R.K., and J.W. Wooten. 1981. Aquatic and Wetland Plants of Southeastern United States. University of Georgia Press, Athens, GA. Grell, A.G., M.G. Shelton, and E. Heitzman. 2005. Changes in plant species composition along an elevation gradient in an old-growth bottomland hardwood-Pinus taeda forest in southern Arkansas. Journal of the Torrey Botanical Society 132:72–89. Howard, A.D. 1990. Theoretical model of optimal drainage networks. Water Resources Research 26:2107–2117. Keddy, P.A., L. Smith, D.R. Campbell, M. Clark, and G. Montz. 2006. Patterns of herbaceous plant diversity in southeastern Louisiana pine savannas. Applied Vegetation Science 9:17–26. Kirkman, L.K., and R.R. Sharitz. 1994. Vegetation disturbance and maintenance of diversity in intermittently flooded Carolina bays in South Carolina. Ecological Applications 4:177–188. Kwit, C., M.W. Schwartz, W.J. Platt, and J.P. Geaghan. 1998. The distribution of tree species in steepheads of the Apalachicola River Bluffs, Florida. Journal of the Torrey Botanical Society 125:309–318. Ludwig, J.A., and J.F. Reynolds. 1988. Statistical Ecology: A Primer on Methods and Computing. John Wiley and Sons, New York, NY. Means, D.B. 1985. The canyonlands of Florida. Nature Conservancy News, Sept./ Oct.:13–17. Means, D.B. 1991. Florida’s steepheads: Unique canyonlands. Florida Wildlife 45:25–28. Means, D.B. 2000. Southeastern US coastal plain habitats of the Plethodontidae: The importance of relief, ravines, and seepage. Pp. 287–302, In R.C. Bruce, R.J. Jaeger, and L.D. Houck (Eds.). The Biology of the Plethodontidae. Plenum Publishing, New York, NY. Mitsch, W.J., and J.G. Gosselink. 2007. Wetlands. 4th Edition. John Wiley and Sons, Inc, New York, NY. 582 pp. Morzaria-Luna, H., J.C. Callaway, G. Sullivan, and J.B. Zedler. 2004. Relationship between topographic heterogeneity and vegetation patterns in a Californian salt marsh. Journal of Vegetation Science 14:523–530. Mulhouse, J.M., D. De Steven, R.F. Lide, and R.R. Sharitz. 2005. Effects of dominant species on vegetation change in Carolina bay wetlands following a multi-year drought. Journal of the Torrey Botanical Society 132:411–420. Platt, W.J., and M.W. Schwartz. 1990. Temperate hardwood forests. Pp. 194–229. In R.L. Myers and J.J. Ewel (Eds.). Ecosystems of Florida. University of Central Florida Press, Orlando, FL. Schumm, S.A., K.F. Boyd, C.G. Wolff, and W.J. Spitz. 1995. A ground-water sapping landscape in the Florida Panhandle. Geomorphology 12:281–297. 298 Southeastern Naturalist Vol. 10, No. 2 Science Applications International Corporation (SAIC). 2006. Revised draft environmental impact statement. Military Family Housing Demolition, Construction, Renovation, and Leasing (DCR & L) Program. Hurlburt Field, Eglin AFB, FL. Sellards, E.H., and H. Gunter. 1918. Geology between the Apalachicola and Ochlockonee Rivers in Florida. Florida Geological Survey. 10th–11th Annual Reports:9–56. Sharitz, R.R. 2003. Carolina bay wetlands: Unique habitats of the southeastern United States. Wetlands 23:550–562. Sharp, H.S. 1938. Steepheads and spring sapping in Florida—Holt and Niceville quadrangles, Florida. Journal of Geomorphology 1:247–248. Tyndall, R.W., K.A. McCarthy, J.C. Ludwig, and A. Rome. 1990. Vegetation of six Carolina bays in Maryland. Castanea 55:1–21. USDA, NRCS. 2007. The PLANTS Database. Available online at http://plants.usda.gov. Accessed 22 December 2007. National Plant Data Center, Baton Rouge, LA. USDA, NRCS. 2010. USDA Geospatial Data Gateway. Available online at http://datagateway. nrcs.usda.gov. Accessed 10 April 2010. National Cartography and Geospatial Center, Fort Worth, TX. US Fish and Wildlife Service. 2007. State and federal threatened, endangered, and other species of concern likely to occur in the Florida Panhandle. Available online at http:// www.fws.gov/ panamacity/resources/specieslist.html. Accessed 14 September 2007. Panama City Fish and Wildlife Service, Panama City, FL. Weeks, H.H., A.G. Hyde, A. Roberts, D. Lewis, C.R. Peters, R.C. Williams, W.L. Pittman, and G.W. Allen. 1980. Soil survey of Santa Rosa County, Florida. United States Department of Agriculture Soil Conservation Service. Wolfe, S.H., J.A. Reidenauer, and D.B. Means. 1988. An ecological characterization of the Florida Panhandle. US Fish and Wildlife Service Biological Report 88(12):1–277. 2011 C.R. Holt, G.W. Folkerts, and D.R. Folkerts 299 Appendix. The following is a list of vascular plant species found in Weaver Creek wetland, Santa Rosa County, FL. Nomenclature follows either the USDA Plants Database (USDA 2007) or the Flora of North America Editorial Committee (1993+). Location of each species within the study area is noted as either upstream (U) or downstream (D). Relative abundances are indicated in parentheses using the following abbreviations: Rare (R), Infrequent (I), Occasional (O), Frequent (F), or Abundant (A). For species found both upstream and downstream, relative abundances are noted for each stream section. The final notation is the collection number for each voucher specimen. LYCOPHYTES LYCOPODIACEAE Lycopodiella alopecuroides (L.) Cranfill (Foxtail Clubmoss) – D(R); Holt 175 PTERIDOPHYTES BLECHNACEAE Woodwardia areolata (L.) T. Moore (Netted Chainfern) – U(O); Holt 115 OSMUNDACEAE Osmunda cinnamomea L. (Cinnamon Fern) – U(O); Holt 126 THELYPTERIDACEAE Thelypteris palustris Schott var. pubescens (Lawson) Fern. (Marsh Fern)– U(R); Holt 165 GYMNOSPERMS CUPRESSACEAE Chamaecyparis thyoides (L.) B.S.P. (Atlantic White-Cedar) – D(A); Holt 141 Taxodium ascendens Brogn. (Pond Cypress) – D(A); Holt 171 PINACEAE Pinus elliottii Engelm. var. elliottii (Slash Pine) – U(A), D(A); Holt 244 ANGIOSPERMS MONOCOTYLEDONS ARACEAE Orontium aquaticum L. (Goldenclub) – D(F); Holt 192 Peltandra sagittifolia (Michx.) Morong (Spoonflower) – D(O); Holt 148 ARECACEAE Sabal minor (Jacq.) Pers. (Dwarf Palmetto) – U(O); Holt 136 BURMANNIACEAE Apteria aphylla (Nutt.) Barnhart ex Small (Nodding Nixie) – U(R); Holt 108 CYPERACEAE Carex atlantica L.H. Bailey (Prickly Bog Sedge) – D(R); Holt 211 Carex elliottii Schwein. & Torr. (Elliott’s Sedge) – D(I); Holt 209 Carex glaucescens Elliot (Southern Waxy Sedge) – D(O); Holt 224 Carex intumescens Rudge (Greater Bladder Sedge) – D(O); Holt 210 Dulichium arundinaceum (L.) Britton (Threeway Sedge) – D(F); Holt 237 Eleocharis elongata Chapm. (Slim Spikerush) – D(O); Holt 221 Rhynchospora capitellata (Michx.) Vahl (Brownish Beaksedge) – D(O); Holt 222 300 Southeastern Naturalist Vol. 10, No. 2 Rhynchospora cephalantha A. Gray (Bunched Beaksedge) – D(O); Holt 235 Rhynchospora chalarocephala Fernald & Gale (Loosehead Beaksedge) – D(I); Holt 185 Rhynchospora corniculata (Lam.) A. Gray (Shortbristle Horned Beaksedge) – D(R); Holt 181 Rhynchospora curtissii Britton (Curtiss’ Beaksedge) – D(R); Holt 174 Rhynchospora filifolia A. Gray (Threadleaf Beaksedge) – D(I); Holt 233 Rhynchospora glomerata (L.) Vahl (Clustered Beaksedge) – U(O), D(O); Holt 117 Rhynchospora gracilenta A. Gray (Slender Beaksedge) – D(O); Holt 155 Rhynchospora macra (C.B. Clarke ex Britton) Small (Large Beaksedge) – D(R); Holt 172 Rhynchospora rariflora (Michx.) Elliot (Fewflower Beaksedge) – D(R); Holt 234 Scirpus cyperinus (L.) Kunth (Woolgrass) – D(I); Holt 200 Scirpus etuberculatus (Steud.) Sojak (Canby’s Bulrush) – D(R); Holt 213 Websteria confervoides (Poir.) S. Hooper (Algal Bulrush) – D(R); Holt 248 ERIOCAULACEAE Eriocaulon decangulare L. (Tenangle Pipewort) – D(A); Holt 146 Lachnocaulon beyrichianum Sporleder ex Koern. (Southern Bogbutton) – D(O); Holt 242 JUNCACEAE Juncus canadensis J. Gay ex Laharpe (Canadian Rush) – D(I); Holt 198 Juncus marginatus Rostk. (Grassleaf Rush) – D(I); Holt 223 Juncus polycephalus Michx. (Manyhead Rush) – D(I); Holt 240 Juncus tenuis Willd. (Path Rush) – D(R); Holt 207 Juncus trigonocarpus Steud. (Redpod Rush) – D(I); Holt 139 LILIACEAE Lilium iridollae Henry (Panhandle Lily) – D(F); Holt 150 Lophiola aurea Ker Gawl. (Goldencrest) – D(F); Holt 218 ORCHIDACEAE Platanthera blephariglottis (Willd.) Lindl. var. conspicua (Nash) Luer (White Fringed Orchid) – D(R); Holt 245 Platanthera cristata (Michx.) Lindl. (Crested Yellow Orchid) – U(I), D(I); Holt 109 POACEAE Aristida patula Chapm. ex Nash (Tall Threeawn) – U(I); Holt 217 Arundinaria gigantea (Walter) Muhl. (Giant Cane) – U(O); Holt 167 Chasmanthium laxum (L.) Yates (Slender Woodoats) – U(R); Holt 120 Dichanthelium dichotomum (L.) Gould var. ensifolium (Baldw. ex Elliot) Gould & C.A. Clark (Cypress Panicgrass) – D(R); Holt 214 SMILACACEAE Smilax laurifolia L. (Laurel Breenbriar) – U(A), D(A); Holt 208 Smilax smallii Morong (Lanceleaf Greenbriar) – U(A), D(A); Holt 157 SPARGANIACEAE Sparganium americanum Nutt. (American Burr-reed) – D(I); Holt 151 XYRIDACEAE Xyris fimbriata Elliot (Fringed Yelloweyed Grass) – D(O); Holt 170 Xyris smalliana Nash (Small’s Yelloweyed Grass) – D(O); Holt 147 2011 C.R. Holt, G.W. Folkerts, and D.R. Folkerts 301 DICOTYLEDONS AQUIFOLIACEAE Ilex coriacea (Pursh) Chapm. (Large Gallberry) – U(F); Holt 112 Ilex glabra (L.) A. Gray (Inkberry) – U(F); Holt 119 Ilex opaca Aiton var. opaca (American Holly) – U(A); Holt 101 Ilex vomitoria Aiton (Yaupon)– U(O), D(O); Holt 116 ASTERACEAE Balduina uniflora Nutt. (Oneflower Honeycombhead) – D(O); Holt 243 Bidens laevis (L.) Britton, Sterns & Poggenb. (Smooth Beggartick) – D(R); Holt 168 BIGNONIACEAE Bignonia capreolata L. (Crossvine) – U(I); Holt 107 CAPRIFOLIACEAE Viburnum nudum L. (Possumhaw) – U(A); Holt 114 CELASTRACEAE Euonymus americanus L. (Bursting-heart) – U(R); Holt 156 CLUSIACEAE Hypericum brachyphyllum (Spach) Steud. (Coastal Plain St. Johnswort) – D(I); Holt 154 Hypericum fasciculatum Lam. (Peelbark St. Johnswort) – D(I); Holt 228 CORNACEAE Cornus florida L. (Flowering Dogwood) – U(R); Holt 129 Cornus foemina Mill. (Stiff Dogwood) – U(O); Holt 160 Nyssa biflora Walter (Swamp Tupelo) – D(O); Holt 144 CYRILLACEAE Cliftonia monophylla (Lam.) Britton ex Sarg. (Black Titi) – U(F); Holt 143 Cyrilla racemiflora L. (White Titi) – U(A); Holt 132 DROSERACEAE Drosera capillaris Poir. (Pink Sundew) –D(O); Holt 189 Drosera intermedia Hayne (Spoonleaf Sundew) – D(I); Holt 158 ERICACEAE Gaylussacia mosieri Small (Woolly Huckleberry) – D(R); Holt 206 Lyonia lucida (Lam.) K. Koch (Fetterbush) – U(A), D(F); Holt 137 Oxydendrum arboreum (L.) DC. (Sourwood) – U(O); Holt 135 Pieris phillyreifolia (Hook.) DC. (Climbing Fetterbush) – D(O); Holt 187 Rhododendron viscosum (L.) Torr. (Swamp Azalea) – U(F), D(O); Holt 204 Vaccinium corymbosum L. (Highbush Blueberry) – U(O); Holt 118 Vaccinium elliottii Chapm. (Elliott’s Blueberry) – U(F); Holt 190 FABACEAE Strophostyles helvola (L.) Elliot (Amberique-bean) – D(R); Holt 227 HAMAMELIDACEAE Hamamelis virginiana L. (Witch-hazel) – U(I); Holt 127 ILLICIACEAE Illicium floridanum Ellis (Florida-anise) – U(A); Holt 194 302 Southeastern Naturalist Vol. 10, No. 2 LAURACEAE Persea palustris (Raf.) Sarg. (Swamp Red Bay) – U(O); Holt 105 LENTIBULARIACEAE Pinguicula primuliflora Alph. Wood & Godfrey (Southern Butterwort) – D(R); Holt 188 Utricularia cornuta Michx. (Horned Bladderwort) – D(R); Holt 226 Utricularia gibba L. (Humped Bladderwort) – D(R); Holt 186 MAGNOLIACEAE Magnolia grandiflora L. (Southern Magnolia) – U(A) Magnolia virginiana L. (Sweet-bay) – U(A), D(O); Holt 106 MELASTOMATACEAE Rhexia petiolata Walter (Fringed Meadowbeauty) – D(I); Holt 197 MYRICACEAE Morella cerifera (L.) Small (Wax Myrtle) – U(A), D(I); Holt 102 Morella caroliniensis (Mill.) Small (Southern Bayberry) – U(O); Holt 128 Morella inodora (Bartram) Small (Odorless Bayberry) – U(I), D(R); Holt 130 NYMPHAEACEAE Nuphar lutea (L.) Sm. subsp. ulvacea (G.S. Mill. & Standl.) E.O. Beal (Yellow Pond-lily) – D(O); Holt 152 Nymphaea odorata Aiton (Fragrant Water-lily) – D(I); Holt 182 OLEACEAE Osmanthus americanus (L.) Benth. and Hook. f. ex A. Gray (Devilwood) – U(F); Holt 205 ONAGRACEAE Ludwigia maritima Harper (Seaside Primrose-willow) – D(R); Holt 219 POLYGALACEAE Polygala brevifolia Nutt. (Littleleaf Milkwort) – D(I); Holt 169 Polygala hookeri Torr. & A. Gray (Hooker’s Milkwort) – D(I); Holt 230 ROSACEAE Photinia pyrifolia (Lam.) K.R. Robertson and Phipps (Red Chokeberry) – D(R); Holt 246 RUBIACEAE Mitchella repens L. (Partridgeberry) – U(I); Holt 122 SARRACENIACEAE Sarracenia leucophylla Raf. (White-top Pitcher Plant) – D(O); Holt 145 Sarracenia psittacina Michx. (Parrot Pitcher Plant) – D(O); Holt 191 Sarracenia pupurea L. (Purple Pitcher Plant) – D(O); Holt 195 Sarracenia rubra Walt. subsp. gulfensis Schnell (Gulf Coast Red Pitcher Plant) – D(O); Holt 149 SAXIFRAGACEAE Itea virginica L. (Virginia Sweetspire) – U(A); Holt 212 VITACEAE Vitis rotundifolia Michx. (Muscadine) – U(F), D(F); Holt 133