Caddo Lake

Plants

brochure Caddo Lake - Plants

Plants of Caddo Lake National Wildlife Refuge (NWR) in Texas. Published by the U.S. Fish & Wildlife Service (USFWS).

Prepared in cooperation with the U.S. Fish and Wildlife Service A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas, March 2011–March 2012 Data Series 854 U.S. Department of the Interior U.S. Geological Survey Cover, Caddo Lake National Wildlife Refuge, Texas, August 2011. A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas, March 2011–March 2012 By Larry Allain Prepared in cooperation with the U.S. Fish and Wildlife Service Data Series 854 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior SALLY JEWELL, Secretary U.S. Geological Survey Suzette M. Kimball, Acting Director U.S. Geological Survey, Reston, Virginia: 2014 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Allain, Larry, 2014, A comprehensive list and photographic collection of the vascular flora of Caddo Lake National Wildlife Refuge, Texas, March 2011–March 2012: U.S. Geological Survey Data Series 854, 41 p., http://dx.doi. org/10.3133/ds854. ISSN 2327-638X (online) iii Contents Abstract ...........................................................................................................................................................1 Introduction ....................................................................................................................................................1 Description of Study Area ............................................................................................................................2 Methods ..........................................................................................................................................................2 Results .............................................................................................................................................................2 Discussion .......................................................................................................................................................9 Summary .......................................................................................................................................................11 Acknowledgments .......................................................................................................................................11 References Cited .........................................................................................................................................11 Photograph Collection (available at http://pubs.usgs.gov/ds/854/) Figures 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Map showing location of Caddo Lake National Wildlife Refuge, Texas ..............................3 Photograph showing chambered pith of black walnut (Juglans nigra), an example of diagnostic plant characters photographed during this project at Caddo Lake National Wildlife Refuge, Texas ...........................................................................4 Photographs showing the differences in leaf form of two varieties of Taxodium distichum occurring on Caddo Lake National Wildlife Refuge, Texas .................................5 Photograph showing pine-hardwood forest predominant on slopes and other well-drained sites in Caddo Lake National Wildlife Refuge, Texas ......................................6 Photograph showing bottomland hardwoods dominated by baldcypress (Taxodium distichum var. distichum) along drainages and in frequently flooded parts of Caddo Lake National Wildlife Refuge, Texas ............................................................6 Photograph showing Chinese tallow tree (Triadica sebifera), an invasive nonnative species that is currently controlled by refuge management at Caddo Lake National Wildlife Refuge, Texas ........................................................................................7 Photograph showing staff of Caddo Lake National Wildlife Refuge, Texas, using herbicide to treat small Chinese tallow trees (Triadica sebifera) before these nonnative, highly invasive trees can bear seeds and colonize additional area ................8 Photograph showing an invasive understory shrub, sacred bamboo (Nandina domestica), that was collected on a small outholding of Caddo Lake National Wildlife Refuge, Texas, north of Texas Farm to Market Road 2198 (FM 2198) ....................9 Photograph showing giant salvinia (Salvinia molesta), considered one of the world’s worst aquatic pests ........................................................................................................9 Photograph showing a three-toed box turtle (Terrapene carolina triunguis), so named because of the number of toes on the back feet, at Caddo Lake National Wildlife Refuge, Texas ...............................................................................................................10 Photograph showing American lady butterfly (Vanessa virginiensis) nectering on the flowers of groovestem Indian plantain (Arnoglossum plantagineum) on a roadside along the Auto Route in Caddo Lake National Wildlife Refuge, Texas .............10 iv Tables 1. Comprehensive list of vascular plants identified at Caddo Lake National Wildlife Refuge, Texas, March 2011–March 2012 ................................................................................12 2. List of nonnative plant species occurring at Caddo Lake National Wildlife Refuge, Texas, March 2011–March 2012 ...............................................................................................28 3. List of vascular plant species found at Caddo Lake National Wildlife Refuge, Texas, March 2011–March 2012, with food value for wildlife .............................................30 Conversion Factors Inch/Pound to SI Multiply By To obtain Length mile (mi) 1.609 kilometer (km) SI to Inch/Pound Multiply By To obtain Area hectare (ha) 2.471 acre A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas, March 2011–March 2012 By Larry Allain Abstract A floristics inventory was conducted to identify and photograph the vascular plants occurring at Caddo Lake National Wildlife Refuge (NWR), Texas, from March 2011 to March 2012 by the U.S. Geological Survey in cooperation with the U.S. Fish and Wildlife Service. This research resulted in the identification of 511 taxa of vascular plants representing 111 families and 317 genera. Despite the degree of development of the refuge at the time it was transferred to the U.S. Fish and Wildlife Service, plant diversity was high. Of the 511 species identified in this study, 346 species are new records for Harrison County, and 3 species are new discoveries for Texas. Caddo Lake NWR is primarily forested with 55 tree species and 35 shrub species identified in this study. Of the species identified, 289 are associated with wetlands having a wetland classification of facultative or wetter, possibly reflecting the proximity of Caddo Lake to the refuge and the three streams that intersect the refuge. Sixty-two of the species found on the refuge are introduced. Chinese tallow tree (Triadica sebifera) is one of the more common invasive tree species on the refuge and is actively controlled by refuge staff. Chinese privet (Ligustrum sinense), sacred bamboo (Nandina domestica), and King’s Ranch bluestem (Bothriochloa ischaemum var. songarica) are present on the refuge and have the potential to become invasive. More than 10,000 photographs were taken of the plants found on the refuge in an effort to document general appearance and capture diagnostic characters of each plant species. Photographs were also taken of many of the animals and landscapes encountered during the project. Select images of each of the plants and animals are included in the collection of more than 1,600 photographs (all photographs by Larry Allain). Introduction The National Wildlife Refuge System was established to manage lands and waters in the United States for conservation and restoration of fish, wildlife, and plant resources. There are 560 national wildlife refuges in all, covering 61 million hectares nationwide (U.S. Fish and Wildlife Service, 2013). Individual refuges are unique and established for a variety of purposes including the protection of endangered species; the preservation of habitat for plants and animals threatened by development or overutilization; the creation of habitat connections and corridors within landscapes for migratory animals; use as a recreational destination for hunting, fishing, wildlife observation, and photography; facilitating environmental education and interpretation; and restoring lands and waters that have been damaged by past use. Most national wildlife refuges have become general refuges for every kind of wildlife that can appropriately be sheltered in that environment. Maintaining and improving habitat quality require that the biological integrity, diversity, and environmental health of refuge resources be conserved. To achieve these goals, each refuge is required by the National Wildlife Refuge System Administration Act of 1997 to develop a 15-year comprehensive conservation plan. Implementation of these plans requires the use of adaptive management that relies on surveys, inventory and monitoring of resources, management practices, and experiments. The information gained is then used to alter and refine management practices. A critical component of this process includes the development of a comprehensive list of the vascular plant species that occur on a refuge. Management goals are affected when endangered species are identified. Managing and restoring habitat require knowledge of existing plant communities and the species they contain. Monitoring invasive plant populations is necessary for their control or eradication, and controlling new invasive plant problems is most efficient when they are detected early in the invasion cycle. Plant monitoring is performed by refuge personnel, partners, and cooperators as budgets allow and is greatly facilitated by a comprehensive plant list. In addition to a plant list, refuge personnel often seek plant information that would assist them in meeting their management goals. Useful plant information might include wildlife use, wetland affinity, and key characters that allow differentiating species in the field. These data can be compiled from existing publications. 2   A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas From March 2011 to March 2012, the U.S. Geological Survey in cooperation with the U.S. Fish and Wildlife Service collected, identified, and photographed the vascular plants occurring at Caddo Lake National Wildlife Refuge (NWR), Texas. The goal of this project was to identify all vascular plant species occurring at Caddo Lake NWR and to take original photographs of each species while synthesizing information on field identification traits and wildlife use. Description of Study Area Caddo Lake NWR is located in Harrison County, Tex., on lands transferred in October 2000 from the Department of Defense, formerly the Longhorn Army Ammunition Plant (fig. 1). The refuge was established on the less contaminated portions of the retired munitions facility for the purpose of converting the site to habitat for birds, fish, and other wildlife. The 3,440-hectare refuge is divided by three drainages, Goose Prairie Creek, Central Creek, and Harrison Bayou, that flow north and east into Caddo Lake (U.S. Fish and Wildlife Service, 2012). It is located in the pineywoods vegetation area of northeast Texas (Hatch and others, 1990). A rolling ridge and swale landscape, created by these drainages, provides a variety of forest types and wetlands in this ancient drowned river valley. Caddo Lake, a 10,850-hectare cypress swamp, borders the refuge on its eastern boundary (fig. 1). The soils are primarily sandy loams with clay-loam occurring in the drain bottoms. Forest types range from baldcypress (Taxodium distichum var. distichum) in the lower parts of Harrison Bayou to mixed pine-hardwoods on the slopes and pinedominated uplands. Shortleaf pine (Pinus echinata) savanna is thought to have been the dominant plant community on the highest elevations of the refuge, but these areas have largely been reforested with loblolly pine (Pinus taeda). Refuge management goals include restoring shortleaf pine savanna by selective logging of loblolly pine and hardwoods. Methods Field trips were made monthly from March 2011 to March 2012. Areas with variable hydrology, slope, elevation, and history were identified from maps and interviews with refuge personnel to select prospective sites for floristic surveys. Selected areas were explored during each sampling trip along with additional areas as time allowed. Individual plants were photographed in the field, and plant specimens were collected for laboratory inspection when identity was uncertain. Voucher specimens are housed at the U.S. Geological Survey National Wetlands Research Center Herbarium in Lafayette, Louisiana. Plant identifications were validated by using Correll and Johnston (1979), Flora of North America Editorial Committee (1993+), and various other manuals. Whether or not a species had been recorded for Harrison County, Tex., was based on collection location maps in the U.S. Department of Agriculture (USDA) PLANTS database (http://plants.usda.gov/). Plant morphological characters found to be diagnostic in field identification were photographed for illustration purposes (fig. 2). Images were organized and labeled by species scientific names based on the Integrated Taxonomic Information System (http://www.itis. gov/). Animals were photographed when encountered. Animal images were cataloged by scientific name when known and by common name when not. Insect identification was accomplished by using Arnett (1993) and BugGuide (2012). Results In the course of this study, 792 plant specimens were collected, identified, and labeled. More than 10,000 plant photographs and 622 animal photographs were taken at the refuge. The photograph collection in this report includes more than 1,600 select plant, animal, and landscape images (all photographs by Larry Allain). This floristic inventory resulted in the identification of 511 taxa of vascular plants representing 111 families and 317 genera (table 1 at end of report). Phylogenetic families representing the greatest species count or diversity were the Asteraceae with 68, Poaceae with 62, Fabaceae with 43, Cyperaceae with 30, Rosaceae with 16, Rubiaceae with 14, Euphorbiaceae with 12, Lamiaceae with 12, Onagraceae with 12, Apiaceae with 10, and Scrophulariaceae with 9 species. The genera with the most species were Carex with 13, Juncus with 9, Quercus with 8, Ludwigia with 7, Paspalum with 7, and Polygonum with 6 species. Results   3 94°00' MARION COUNTY 2198 Goose Prairie Creek Caddo Lake Central Creek CADDO LAKE NATIONAL WILDLIFE REFUGE Study area Gu lf of M ex ico TEXAS CADDO PARISH LOUISIANA HARRISON COUNTY TEXAS 43 Harrison Bayou 32°30' Base modified from U.S. Geological Survey 1:24,000 quadrangle digital data Universal Transverse Mercator, zone 14 North American Datum of 1983 EXPLANATION Caddo Lake National Wildlife Refuge Auto Route Figure 1. Location of Caddo Lake National Wildlife Refuge, Texas. 0 0 5 MILES 5 KILOMETERS 4   A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas Figure 2. Chambered pith of black walnut (Juglans nigra), an example of diagnostic plant characters photographed during this project at Caddo Lake National Wildlife Refuge, Texas. Compound leaves of this tree are similar to leaves of hickories (Carya spp.), which can be distinguished by having solid pith in their twigs. Results   5 Of the 511 species identified in this study, 346 are new records for Harrison County. According to the USDA PLANTS database, three species, peelbark St. Johnswort (Hypericum fasciculatum), changing forget-me-not (Myosotis discolor), and pond cypress (Taxodium distichum var. imbricarium) (fig. 3), are new to Texas. One species, Scleria ciliata var. ciliate, is listed for Texas by Hatch and others (1990) and one species, Pyrus calleryana, by Correll and Johnston (1979), but no locations are listed in the USDA PLANTS database for these two species. Most of Caddo Lake NWR is forested with 56 tree species and 33 shrub species identified in this study. Forest types vary from pine forests on ridge tops to baldcypress swamp flooded forests in creek bottoms and within the frequently flooded sites near Caddo Lake. Pine-hardwood forest dominates on slopes and much of the upland and well-drained areas of Caddo Lake NWR (fig. 4). In pinehardwood forest, loblolly and shortleaf pine occur in association with such hardwood species as southern red oak (Quercus falcata), post oak (Quercus stellata), sweetgum (Liquidambar styraciflua), water oak (Quercus nigra), willow oak (Quercus phellos), white oak (Quercus alba), sugarberry (Celtis laevigata), blackgum (Nyssa sylvatica), and winged elm (Ulmus alata). Common understory shrub species in pine-hardwood forest include hawthorns (Crataegus sp.), American holly (Ilex opaca), waxmyrtle (Morella cerifera), farkleberry (Vaccinium arboreum), red buckeye (Aesculus pavia), flowering dogwood (Cornus florida), eastern redbud (Cercis canadensis), sassafras (Sassafras albidum), southern A sugar maple (Acer barbatum), and American beautyberry (Callicarpa americana). Those species most common in ground cover vegetation are sedges (Carex spp. and Cyperus spp.), tick trefoil (Desmodium spp.), elephantsfoot (Elephantopus spp.), woodoats (Chasmanthium spp.), and panicums (Panicum spp. and Dichanthelium spp.). On the forest edge, vines predominate, with peppervine (Ampelopsis arborea), Virginia creeper (Parthenocissus quinquefolia), Alabama supplejack (Berchemia scandens), greenbriars (Smilax spp.), poison ivy (Toxicodendron radicans), and grapes (Vitis spp.) being most common. Tree species that occurred in low areas along creek drainages and in frequently flooded parts of the refuge include baldcypress, overcup oak (Quercus lyrata), water oak, willow oak, green ash (Fraxinus pennsylvanica), bitter pecan (Carya aquatica), and sweetgum (fig. 5). Common smaller trees and shrubs include planertree (Planera aquatica), swamp privet (Forestiera acuminata), water locust (Gleditsia aquatic), buttonbush (Cephalanthus occidentalis), and possumhaw (Ilex decidua). Herbaceous ground cover in wet areas included mostly sedges, rushes (Juncus spp.), smartweeds (Persicaria spp.), heliotrope (Heliotropium indicum), camphorweeds (Pluchea spp.), lizard’s tail (Saururus cernuus), primrosewillows (Ludwigia spp.), and rosemallow (Hibiscus moscheutos ssp. lasiocarpos). Vines most common in these areas were climbing hempvine (Mikania scandens), buckwheat vine (Brunnichia ovata), and climbing dogbane (Thyrsanthella difformis). B Figure 3. The differences in leaf form of two varieties of Taxodium distichum occurring on Caddo Lake National Wildlife Refuge, Texas. A, Taxodium distichum var. imbricarium, a new taxon for Texas, has scale-like leaflets on upward oriented leaves. B, Taxodium distichum var. distichum has descending leaves and linear leaflets. 6   A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas Figure 4. Pine-hardwood forest predominant on slopes and other well-drained sites in Caddo Lake National Wildlife Refuge, Texas. Figure 5. Bottomland hardwoods dominated by baldcypress (Taxodium distichum var. distichum) along drainages and in frequently flooded parts of Caddo Lake National Wildlife Refuge, Texas. Results   7 Many of the vascular plants that occur in shortleaf pine understory were present on the refuge, but most were uncommon. Grasses, growing mostly on roadsides and that are associated with savanna understory, include splitbeard bluestem (Andropogon ternarius), woodoats, little bluestem (Schizachyrium scoparium), switchgrass (Panicum virgatum), prairie panicgrass (Panicum brachyanthum), brownseed paspalum (Paspalum plicatulum), eastern gamagrass (Tripsacum dactyloides), purpletop (Tridens flavus), arrowfeather three-awn (Aristida purpurascens), and rosette grasses (Dichanthelium spp.). Several conservative species usually confined to undisturbed shortleaf pine understory and prairies were identified, including nodding lady’s tresses (Spiranthes cernua), dwarf sundew (Drosera brevifolia), and pinkscale blazing star (Liatris elegans). Other wildflowers of pine savanna occurred in small populations such as sidebeak pencilflower (Stylosanthes biflora), diamond flowers (Stenaria nigricans), multibloom hoarypea (Tephrosia onobrychoides), roughleaf coneflower (Rudbeckia grandiflora), hairyflower spiderwort (Tradescantia hirsutiflora), Carolina anemone (Anemone caroliniana), groovestem Indian plantain (Arnoglossum plantagineum), and butterfly milkweed (Asclepias tuberosa). Wetland indicator status (Lichvar, 2013) of the taxa identified in this study indicated that most of the species are wetland plants, possibly reflecting the proximity of Caddo Lake and the three streams that intersect the refuge. While 222 species were categorized as upland or facultative upland plants, 289 are associated with wetlands with 122 facultative, 78 facultative wet, and 82 obligate wetland species. Of the 511 taxa identified in this study, 62 were introduced (table 2 at end of report). Most nonnative species have become naturalized and make up a small part of the flora, although several are invasive and pose a risk to native vegetation and wildlife habitat quality. Chinese tallow tree (Triadica sebifera) is highly invasive and is a management priority for refuge staff (figs. 6 and 7). Other nonnative trees including flowering pear (Pyrus calleryana), silk tree (Albizia julibrissin), and Chinaberry tree (Melia azedarach) are Figure 6. Chinese tallow tree (Triadica sebifera), an invasive nonnative species that is currently controlled by refuge management at Caddo Lake National Wildlife Refuge, Texas. Pictured here in the fall of the year is a branch bearing white seeds and leaves beginning to turn colors. present but do not appear to pose a risk of becoming invasive. Chinese privet (Ligustrum sinense) is present and has not yet become invasive at Caddo Lake NWR. Elsewhere in east Texas forests, Chinese privet has become a nuisance invader in forest understory. Another understory shrub with a history of invasion, sacred bamboo (Nandina domestica), was rare on the refuge but should be part of an active eradication program (fig. 8). While numerous nonnative forbs and grasses bloom on the roadsides of Caddo Lake NWR, one grass species is problematic. King’s Ranch bluestem or KR bluestem (Bothriochloa ischaemum var. songarica) has spread eastward and northward from south Texas along roadsides in the past 15–20 years colonizing disturbed grasslands, roadsides, and old agricultural fields. Mowing may speed its spread, and it has the potential to exclude other species. Without a control strategy, the diverse and colorful variety of wildflowers lining the roads at Caddo Lake NWR may become a monoculture of KR bluestem. 8   A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas Figure 7. Staff of Caddo Lake National Wildlife Refuge, Texas, using herbicide to treat small Chinese tallow trees (Triadica sebifera) before these nonnative, highly invasive trees can bear seeds and colonize additional area. Discussion   9 Figure 8. An invasive understory shrub, sacred bamboo (Nandina domestica), that was collected on a small outholding of Caddo Lake National Wildlife Refuge, Texas, north of Texas Farm to Market Road 2198 (FM 2198). Giant salvinia (Salvinia molesta), considered one of the world’s worst aquatic pests (Oliver, 1993), has become a major problem in Caddo Lake (fig. 9). A native of Brazil (Everitt and others, 2007), giant salvinia impedes navigation and reduces sunlight and oxygen, killing beneficial plants, insects, and fish. It can clog agricultural irrigation ditches Figure 9. Giant salvinia (Salvinia molesta), considered one of the world’s worst aquatic pests. It has become a major problem on Caddo Lake at Caddo Lake National Wildlife Refuge, Texas. and impair electrical generation (Holm and others, 1977). Experimental research is being conducted by the Caddo Lake Institute in cooperation with Caddo Lake NWR to investigate the use of a beetle (Cyrtobagous salviniae) for biological control of this aggressive weed. In addition to wild species, planted species were also collected and photographed during this project. A live oak tree (Quercus virginiana) apparently planted as a landscape specimen near the refuge office was the only individual of that species occurring on the refuge. Indian paintbrush (Castilleja indivisa) and firewheel (Gaillardia pulchella) growing on the roadside at the entrance of the refuge are commonly planted on roadsides in Texas and were not found elsewhere on the refuge. A combination of plant species including Illinois bundleflower (Desmanthus illinoensis), plains snakecotton (Froelichia floridana), and Maximilian sunflower (Helianthus maximiliani) dominated the road median in front of the refuge office and was reported to be the results of a grassland planting conducted by Texas Parks and Wildlife Department (Jason Roesner, assistant refuge manager, oral commun., 2011). Plant species thought to have been planted are labeled in table 1. Discussion Despite the developed nature of the Longhorn Army Ammunition Plant at the time it was transferred to the U.S. Fish and Wildlife Service, considerable plant diversity can be found at the refuge. Forest types range from pine-hardwood on ridges to cypress-dominated bottomland hardwoods along the three drainages and the lake margin. Diverse communities of herbaceous plant species on roadsides and in forest clearings include remnant species common in predevelopment plant communities, as well as ruderal species. In the wettest areas of the refuge, plants such as smartweeds (Persicaria spp.) and primrose willows (Ludwigia spp.) provide food for overwintering waterfowl (table 3 at end of report). Diverse grassy areas provide quality habitat for grassland species. Occasional deer, wild turkeys, northern bobwhite (Colinus virginianus), eastern cottontail (Sylvilagus floridanus), coyote (Canis spp.), gray (Sciurus carolinensis) and fox (Sciurus niger) squirrels, and numerous other animals can be glimpsed along the Auto Route (a 6-mile-long auto tour through a small portion of the refuge; fig. 1). At the western end of their range at Caddo Lake NWR, three-toed box turtles (Terrapene carolina triunguis) can sometimes be seen in open forest or on roadsides, especially during their March and April breeding season (fig. 10). 10   A Comprehensive List and Photographic Collection of the Vascular Flora of Caddo Lake National Wildlife Refuge, Texas Figure 10. A three-toed box turtle (Terrapene carolina triunguis), so named because of the number of toes on the back feet, at Caddo Lake National Wildlife Refuge, Texas. Their range extends from east Texas to the Florida Panhandle. Numerous species of birds reside year-round or migrate through the refuge during spring and fall including eastern bluebird (Sialia sialis), American woodcock (Scolopax minor), yellow-breasted chat (Icteria virens), rufous-sided towhee (Pipilo erythrophthalmus), and white-throated sparrow (Zonotrichia albicollis). Butterflies and numerous other insects can be seen along the roadsides in spring and fall (fig. 11). Widening of grassy areas along the refuge’s Auto Route and other interior roads could provide additional habitat for native pollinators and other grassland insect species. Roadsides within the refuge provide a colorful show of wildflowers. Trees, with their leaf, flower, and seed displays, create a vivid natural experience for visitors. Many of the species listed as constituents of shortleaf pine understory are present on the refuge and could be restored as part of the refuge’s goal of restoring shortleaf pine savanna. Such a restoration strategy would enhance the value of these forests for wildlife, as well as create a more rewarding experience for refuge visitors. Figure 11. American lady butterfly (Vanessa virginiensis) nectering on the flowers of groovestem Indian plantain (Arnoglossum plantagineum) on a roadside along the Auto Route in Caddo Lake National Wildlife Refuge, Texas. A wide variety of butterflies and skippers occur on the refuge. References Cited  11 Summary From March 2011 to March 2012, vascular plants were collected and photographed at Caddo Lake National Wildlife Refuge (NWR), Texas, to produce a floristic inventory. The goal of this project was to create both a comprehensive list of the refuge’s vascular flora and a photographic record of each plant species. This plant inventory resulted in the identification of 511 taxa of vascular plants representing 111 families and 317 genera. Of the species identified in this study, 346 are new records for Harrison County. Caddo Lake NWR is primarily forested with 56 tree species and 33 shrub species identified in this study. Of the plant species identified, 289 are associated with wetlands having a wetland classification of facultative or wetter. Sixty-two of the species found on the refuge are introduced, including the invasive Chinese tallow tree (Triadica sebifera), Chinese privet (Ligustrum sinense), sacred bamboo (Nandina domestica), and King’s Ranch bluestem (Bothriochloa ischaemum var. songarica). More than 10,000 photographs were taken of plants found on the refuge in an effort to document general appearance, as well as the diagnostic characters of each plant species. Photographs were also taken of wildlife encountered during the collective field trips. Of the photographs taken, more than 1,600 select digital images of plants, animals, and landscapes are included in the photograph collection (all photographs by Larry Allain). Acknowledgments Correll, D.S., and Johnston, M.C., 1979, Manual of the vascular plants of Texas: The University of Texas at Dallas, 1,880 p. Everitt, J.H., Lonard, R.L., and Little, C.R., 2007, Weeds in south Texas and northern Mexico: Lubbock, Texas Tech University Press, 240 p. Flora of North America Editorial Committee, eds., 1993+, Flora of North America—North of Mexico: New York, Oxford University Press, 16+ v. Hatch, S.L., Gandhi, K.N., and Brown, L.E., 1990, Checklist of the vascular plants of Texas: College Station, Texas Agricultural Experiment Station, 158 p. Holm, L.G., Plucknett, D.L., Pancho, J.V., and Herberge, J.P., 1977, The world’s worst weeds: Honolulu, University Press of Hawaii, 609 p. Lay, D.W., 1969, Foods and feeding habits of white-tailed deer, in Halls, L.K., ed

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