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.
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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