Riverscour is an eclectic assemblage of highly biodiverse riparian natural communities that share characteristics with grasslands, savannas, glades, wetlands, and floodplains. We define "riverscour" as "open riparian habitats of rocky, stable-substrate (bedrock, boulder, cobble) zones, often along high-gradient streams, where periodic high-energy flows (water, ice, debris) and edaphic factors inhibit woody vegetation and promote persistent grassland-shrubland-open woodland-outcrop communities rich in conservative heliophytes." A key factor distinguishing riverscour from gravel and sand bars and other floodplain habitats is that these areas are underlain by more stable substrates, which resist structural reworking by floodwaters. Within Eastern Unglaciated North America, we mapped 1322 stream reaches totaling 2385.8 km containing riverscour. Given their small size, these communities support a disproportionately large number of rare, endemic, and undescribed species. For example, within a five-county area in Tennessee, riverscour makes up significantly less than 1% of the area but contributes at least 37 (25%) of the region's 150 state- and federally-listed vascular plant species. There are numerous threats to riverscour, the greatest being inundation caused by impoundment of rivers and associated downstream hydrologic alterations. Interruption of scouring processes associated with flooding and/or ice promotes succession toward larger woody species and away from open herbaceous/shrub-dominated vegetation. Other threats include invasive species, recreation pressure, and climate change. These threats, coupled with high biodiversity and historical losses, make protection and proper management of riverscour ecosystems especially important in conserving the native biodiversity of eastern North America.

Rhynchospora nivea and Saururus cernuus are reported as new to Mexico. Both species were collected on the Río Bravo del Norte in Coahuila, while Saururus is additionally reported from Volcán Jorulla, Michoacán. The entire distribution of each species is also discussed.

First posted May 20, 2021 For additional information, contact: Director, Lower Mississippi-Gulf Water Science CenterU.S. Geological Survey640 Grassmere Park Drive Nashville, TN 37211 The unglaciated southeastern United States is a biodiversity hotspot, with a disproportionate amount of this biodiversity concentrated in grasslands. Like most hotspots, the Southeast is also threatened by human activities, with the total reduction of southeastern grasslands estimated as 90 percent (upwards to 100 percent for some types) and with many threats escalating today. This report summarizes the results of a multistakeholder workshop organized by the Southeastern Grasslands Initiative and the U.S. Geological Survey, held in January 2020 to provide a scientific needs assessment to help inform the Species Status Assessment (SSA) process under the U.S. Endangered Species Act, with a focus on grassland species and communities of conservation concern in the southeastern United States. This report reviews the ecology of southeastern grasslands, including influences on their origin, maintenance, and high species richness and endemism; presents findings from the workshop; and discusses science questions, hypotheses, and possibilities for future research projects to help fill key knowledge gaps.Participants in the January 2020 workshop, representing diverse expertise in various topics in southeastern grassland ecology, were tasked with identifying major threats to grassland species in the Southeast as well as potential ways to make the SSA process more efficient and effective. An underlying assumption and starting place for workshop discussion was that an ecosystem-based approach to the SSA process is more cost-efficient than a species-by-species approach, in large part because many species with similar biological requirements can be addressed by the same actions. Nevertheless, one partner in this effort, the U.S. Fish and Wildlife Service, does require specific attention be given to taxa that have been petitioned for Federal listing, though as often as possible these taxa are considered alongside a larger group of priority taxa with an ecosystem approach.For group discussions, workshop participants followed a modified “World Café” method, a structured conversational approach for knowledge sharing. Group discussions focused on five categories of threats to grassland communities and species: (1) habitat loss, fragmentation, and disruption of functional population connectivity; (2) climate change, especially changes in temperature and precipitation, including intensity and seasonality, and impacts on soil moisture, groundwater levels, and other ecosystem parameters; (3) changes to disturbance regimes, as influenced by climate and land-use change, extinctions, and human attitudes and behaviors; (4) invasive species (not limited to nonnative species); and (5) localized or subregional impacts such as sea-level rise. In addition to group discussions, workshop participants—as well as other grassland experts who were unable to attend the workshop—completed a preworkshop survey concerning challenges and opportunities for grassland conservation. Findings reported here under each of these topics represent ideas, problems, hypotheses, and questions identified by a diverse community of grassland managers and researchers which may be addressed by future research and monitoring in southeastern grassland ecosystems to help guide science-based conservation of grassland-dependent species.

Rediscovery of the Texas endemic Chloris texensis in Brazoria County, and new records for Ft. Bend, Matagorda, and Waller counties are documented. Collection records outside the narrow Upper Coastal Prairie distribution are also reviewed.

In support of natural resource agencies in Canada, the United States, and Mexico, we report on a series of component analyses and an updated Landscape Conservation Design for temperate grassland conservation. We targeted 12 major grassland ecosystem types that occur across the Great Plains and Chihuahuan Desert regions. Component analyses included (1) documenting long-term trends in extent by grassland type, (2) identifying species of concern associated with the major grassland types, (3) documenting current protected areas including each grassland type, (4) assessing landscape intactness and connectivity among grassland areas, and (5) identifying Grassland Potential Conservation Areas (GPCAs) to advance grassland conservation. Most severe declines in grassland extent have occurred in tallgrass prairie types, followed by mixed-grass, shortgrass, and semi-desert grasslands. Similar trends by type were documented for landscape intactness and connectivity. Some 174 species of vertebrates, invertebrates, and plants considered by NatureServe as critically imperiled, imperiled, or vulnerable are strongly associated with these grassland types, and 103 are listed under protective legislation in one or more countries. Just 1.2% of historic extent for all types combined is currently found within designated protected areas. A total of 177 GPCAs were identified to represent grassland type diversity in areas least likely to conflict with other land uses. Within identified GPCAs, type-specific representation varied from a low of just 1% of historic extent for Texas Blackland Tallgrass Prairie to a high of 27% for Western Great Plains Sand Prairie. Combined across all 12 grassland types, 15% of historic extent is represented.

Arctium minus, a European native, is currently known to have been introduced throughout most of continental United States except for Florida, Delaware, and Texas. The species is reported in Texas in the Flora of North America, but without specimen documentation. Numerous historical nomenclature complexities and confusion involved in proper documentation of this species’ spread and distribution are discussed. It is here reported as new to Texas, based upon a collection in Oldham County in the northern Panhandle. The species is considered to be weedy and may have the potential to be invasive in the High Plains and Rolling Plains regions of Texas. Brief descriptions of historic distribution and spread based on early botanical literature, and various economic and ecological associations of A. minus are summarized.

Field studies at the Lawther - Deer Park Prairie Preserve, an area of approximately 21 ha (51 acres) of the Gulf Coast Prairies and Marshes vegetation area, have resulted in a description of the vegetation associations and an annotated checklist of the vascular flora. Six plant community associations occur on the property: (1) the Upper Texas Coast Ingleside Sandy Wet Prairie; (2) Eastern Gamagrass - Switchgrass - Yellow Indiangrass Herbaceous Vegetation; (3) Gulf Cordgrass Herbaceous Vegetation; (4) Texas Gulf Coast Live Oak - Sugarberry Forest; (5) Little Bluestem - Slender Bluestem - Big Bluestem Herbaceous Vegetation, and (6) Natural Depressional Ponds. The checklist includes 407 species belonging to 247 genera and 86 families. Forty-six species are non-native. The best-represented families (with species number following) are Poaceae (84), Asteraceae (68), Cyperaceae (33), and Fabaceae (19). West Gulf Coastal Plain (eastern Texas and western Louisiana) endemics include Helenium drummondii, Liatris acidota, Oenothera lindheimeri, and Rudbeckia texana. One Texas endemic, Chloris texensis, a Species of Greater Conservation Need, is present. Other noteworthy species are Andropogon capillipes, Digitaria texana, and Platanthera nivea.

Ajuga chamaepitys is reported as naturalized in a horse pasture along the east rn banks of White Oak Creek in Gillespie County of the Edwards Plate au. This is the second naturalized species of Ajuga known in Texas. The restricted distribution of this speci es suggests that it was established by adulterated forage transported with horse stock. Ongoing floristic inventory in the Edwards Plateau of southcentral Texas has resulted in the discovery of naturalized populations of Ajuga chamaepitys (L.) Schreb. This is the third state of the USA where this species has been documented (Virgina, Mar yland, and Texas). Voucher specimens: TEXAS. Gillespie Co.: Terra Linda Estates, ca. 15 km at 356 de grees from Kerrville (Kerr Co.), lat. 30°10’43.58”, long. 99°08’55.62”, ca. 595 m elev., 6 Apr 2015, W.C. Holmes, J.R. Singhurst & J.N. Mink 16134 (BAYLU); same general location, lat. 30°11 ʹ0 .22”̎, long. 99°08’41.63”, same collectors and date, 16135 (BAYLU); same general location , lat. 30°11’18.68”, long. 99°08’11.30”, same collectors and date, 16130 (BAYLU). Figure 1. The Gillespie County pasture, which is about 1.9 km long and va ries from about 50 to 230 m in width, was densely and evenly covered with Ajuga. Associated vegetation within the pasture included Nassella leucotricha, Salvia farinacea, Marrubium vulgare, Glandularia bipinnatifida, Verbena halei, Ratibida columnifera, Lesquerella recurvata, Scutellaria drummondii, Arenaria sp., Evax sp., and Chaerophyllum tainturieri. Peripheral herbaceous vegetation and woody shrubs and trees included Desmodium paniculatum, Desmodium psilophyllum, Ulmus crassifolia, Juniperus ashei, Quercus buckleyi, Celtis laevigata, with Taxodium distichum and Platanus occidentalis along the littoral zone of White Oak Creek. The genus Ajuga comprises 40-50 species of decumbent and erect annuals and per e nials in North Africa, Mediterranean Europe, Great Britain, Is rael, Asia, and Australia, distributed mostly in cooler regions (Cheifetz et al. 1999). Ajuga chamaepitys is native to central and southern Europe, the eastern Mediterranean region, and North Africa. None f the species are native to the Western Hemisphere (Diggs et al. 1999). Mink, Singhurst, and Holmes: Ajuga chamaepitys in Texas 2 Until now, only Ajuga reptans L. was known from Texas (Cory & Parks 1937; Gould 1962; Correll & Johnston 1970; Hatch et al 1990; Johnston 1990; Jones et al. 1997; Turner et al. 2003; Hannick et al 2013). Ajuga chamaepitys was first reported in the USA in 1981 from Virginia (Harvil l et al. 1981) and later from Maryland (Brown & Brown 1984). Th ree other species of Ajuga are known adventives or have escaped cultivation in North America (Radford et al. 1965; Strausbaugh & Core 1977; Kartesz 2015) : (1) A. genevensis, in the northeastern USA and southeastern Canada (Gleason & Cronquist 1991; Brouillet et al. 2006; Kartesz 2015), (2) A. reptans, widespread throughout the USA except the Dakotas, Minnesota, Nebraska, W yoming, Colorado, New Mexico, Nevada, California and Arizona (Gleason & Cronquist 1991; Br ouillet et al. 2006; Kartesz 2015), and (3) A. pyramidalis, known only from Washington County, Mississippi (Bryson & Skojac 2011). The following key, adapted from Stace (1997), distinguishes the thr ee species in the southern USA. KEY TO AJUGA NATURALIZED IN SOUTHERN USA 1. Annuals; leaves dissected; plants neither stoloniferous no r rhiz matous; corollas yellow ..................................................................................................... Ajuga chamaepitys 1. Perennials; leaves subentire or serrate; plants stolonif er us or rhizomatous; corollas blue, pink or white. 2. Plants rhizomatous; all bracts longer than flowers; stem puberulence continuous around stems ................................................................................................Ajuga pyramidalis 2. Plants stoloniferous; upper bracts shorter than flowers; upper part of stem puberulence discontinuous around stems (only on 2 opposite sides) ...... ... ........................... Ajuga reptans Ajuga chamaepitys in the Texas flora may remain localized, given its disjunc t pattern of distribution in the USA (Virginia-Maryland and Texas) , coupled with its known edaphic requirements of limestone, calcareous substrates, and calciferous soil (Lousley 1950; Stace 1997). Although Turrill (1948) described a large-scale ecological cline in the geographic distribution of the species from Asia Minor across Europe, this plant is designated by o thers as uncommon, decreasing or restricted in England (Lousley 1950; Stace 1997). Jim Scuddy, land m ager of Terra Linda Estates, observes that the plant has been present in the Gillespie C ounty horse pasture since the 1980s; no dispersal of A. chamaepitys has been observed outside of this area. The establishment of Ajuga chamaepitys in the USA probably is connected to horseracing and horse recreational pursuits and the importation of horse stoc k fr m Europe and the Middle East (Weatherby 1791; Shouse 1908; Prior 1935; Wentworth 1938; Lightcap 1940) –– see ds may have arrived via ruminant gut remnants or adulterated forage. Livestock forage as a vector for plant propagules is well known (Dewey 1897; Hillman & Henry 1928; Clines 2005) and interstate regulations related to weed-free hay are lax. ACKNOWLEDGEMENTS We thank Jim Scuddy, Ranch Manager of Terra Linda Estates , who brought the first sample of the species to Jim and Priscilla Stanley, naturalis ts and residents of Terra Linda Estates. Photos were then passed on to the authors, which led to plans for visiting the site. We also thank Jeff Forman, Wildlife Biologist at Mason Mountain Wildlife M anagement Area (MMWMA), who suggested that the plant might be Ajuga chamaepitys and Bill Carr of the University of Texas Herbarium for confirming the identification. Mink, Singhurst, and Holmes: Ajuga chamaepitys in Texas 3 Figure 1. Ajuga chamaepitys, ground-pine or yellow bugle, in Gillespie Co., Texas, 6 A pril 2015. Photo by Jason Singhurst. LITERATURE CITED Brown, M.L. and R.G. Brown. 1984. Herbaceous Plants of Maryland. Port City Press, Baltimore, Maryland. Brouillet, L., F. Coursol, and M. Favreau. 2006. VASCAN , the Database of Vascular Plants of Canada. Herbier Marie-Victorin, Institut de Recherche e n Biologie Végétale, Univ. de Montréal. Bryson, C.T. and D.A. Skojac, Jr. 2011. An annotated check list of the vascular flora of Washington County, Mississippi. J. Bot. Res. Inst. Texas 5: 855–866. Cheifetz, A., C. Double, L. Barnard, and D. Imwold (eds .). 1999. Botanica’s Complete Annuals & Perennials. Laurel Glen Publishing, San Diego, California. Clines, J. 2005. Preventing weed spread via contaminated hay and straw. Pp 4–6, in G. Skurka, (ed.). Proceedings of the California Invasive Plant Counc il Symposium. Volume 9. California Invasive Plant Council (Cal-IPC), Berkeley. Cory, V.L. and H.B. Parks. 1937. Catalogue of the Flora of Texas. Texas Agric. Exp. Sta. 550, College Station. Correll, D.S. and M.C. Johnston. 1970. Manual of the Vas cul r Plants of Texas. Texas Research Foundation, Renner. Dewey, L.H. 1897. Migration of weeds. Pp. 263–286, in United States Department of Agriculture. Yearbook. Government Printing Office, Washington, D.C. Diggs, G.M., B.L. Lipscomb, and R.J. O’Kennon. 1999. Illustra ted Flora of North Central Texas. Sida Bot. Misc. 16. Bot. Res. Inst. of Texas, Fort Wo rth. Mink, Singhurst, and Holmes: Ajuga chamaepitys in Texas 4 Gleason, H.A. and A. Cronquist. 1991. Manual of Vascular Pl nts of the Northeastern United States and Adjacent Canada. New York Botanical Garden, Bron x, New York. Gould, F.W. 1962. Texas Plants—A Checklist and Ecological Sum mary. Texas Agricultural Experiment Station Publ. MP-585, Agricultural and Mechanical College of Texas, College Station. Hannick, V.C., J.N. Mink, J.R. Singhurst, and W.C. Holme s. 2013. Annotated checklist of the vascular flora of McLennan County, Texas. Phytoneuron 2013–29: 1 37. Harvill, A.M., C.E. Stevens, and D.M.E. Ware. 1981. Atl as of the Virginia flora, Part II. Dicotyledons. Virginia Botanical Associates, Farmville. Hatch, S.L., K.N. Gandhi, and L.E. Brown. 1990. Checklis t of the Vascular Plants of Texas. Texas Agricultural Experiment Station Publ. MP-1655. Texas A&M Univer sity, College Station. Hillman, F.H. and H.H. Henry. 1928. The incidental seed found in commercial seed of alfalfa and red clover. Proceedings of the International Seed Testi ng Association. October, No. 6: 1–20. Johnston, M.C. 1990. The Vascular Plants of Texas: A List, Updating the Manual of the Vascular Plants of Texas (ed. 2). Published by the author, Austin, Te xas. Jones, S.D, J.K. Wipff, and P.M. Montgomery. 1997. Vascular Pl nts of Texas: A Comprehensive Checklist Including Synonymy, Bibliography, and Index. Univ. of Texas Press, Austin. Kartesz, J.T. 2015. Taxonomic Data Center. The Biota of North America Program (BONAP). Chapel Hill, North Carolina. Lightcap, G.C. 1940. The American Thoroughbred. Iowa State Univ. Veterinarian: Vol. 2: Iss. 2, Article 1. Lousley, F.E. 1950. The New Naturalist—Wild Flowers of C halk and Limestone. Collins, London. Prior, C.M. 1935. The Royal Studs of the Sixteenth and Seve nt enth Centuries. Horse and Hound Publications Ltd., London. Radford, A.E., H.E. Ahles, and C.R. Bell. 1965. Atlas of the Vascular Flora of the Carolinas. Univ. of North Carolina, Dept. of Botany Techn. Bull. 165, Chape l Hill. Shouse, J. 1908. The American thoroughbred horse. J. Her ed. 1: 92–106. Stace, C. 1997. New Flora of the British Isles (ed. 2). Cambridge Univ. Press, Cambridge, United Kingdom. Strausbaugh, P.D. and E.L. Core. 1977. Flora of West Vi rginia, (ed. 2 in 4 vols.). West Virginia Bulletin, Morgantown. Turner, B.L., H. Nichols, G. Denny, and O. Doron. 2003. A tlas of the Vascular Plants of Texas,Vol. I. Sida, Bot. Misc. 24. Botanical Res. Inst. of Texas, Fort Worth. Turrill, W.B. 1948. The New Naturalist – British Plant L ife. Collins, London

Pluchea foetida is confirmed as a member of the native flora of Oklahoma . It is documented by three collections from the West Gulf Coastal Plain of Pushmataha County, apparently at the northwestern edge of the distribution of the species. Collect i ns were made during the summer of 2008 and 2014. Pluchea foetida (L.) DC. var. foetida (Asteraceae, Plucheeae), commonly called stinking camphorweed, is distributed in permanently wet soil of the southeast coastal plain of the USA (New Jersey to south Florida, west to south Arkansas, and e st Texas (Cronquist 1980). Nesom (2006) included Hispaniola and Mexico (as have Small 1933 and Fern ald 1950) and southeast Oklahoma as part of the distribution in his treatment of Pluchea for the Flora of North America. The purpose of this paper is to elucidate the distribution of the species i n Oklahoma. Despite being mentioned by Nesom (2006) as occurring in Oklahoma, Pluchea foetida is not included in the Keys to the Flora of Oklahoma (Waterfall 1966), the checklist of the flora of the state (Taylor and Taylor 1994), or Keys and Descriptions for the Vas cul r Plants of Oklahoma (Tyrl et al. 2010), nor is it mapped as part of the Oklahoma flora in USDA, NRCS (2014) or Kartesz (2014). Inquiries to the herbaria most likely expected to possess a specimen (BRIT-SMU, CSU, DUR, UCO, OKL, OSU, TAMU, TEX-LL, and TULS) were successful in locating one specimen at OKL (Hoagland et al. 2004). Based upon specimens cited below, which were recently c ollected, Pluchea foetida is now documented as part of the flora of Oklahoma. Voucher specimens. USA. Oklahoma. Pushmataha County : Junction of Indian Nation Turnpike and Hwy 3, ca. 0.3 mi N of junction of Indian Nati on Turnpike/Hwy 3, E side, 28 Aug 2008, Buthod and Hoagland 7843 (OKL); 0.4 mi N of the jct of OK Hwy 3 and Indian Nation Turnpike on Indian Nation Turnpike in hillside bog in right of wa y on the E side of Indian Nation Turnpike (34° 14'25.78" N, 95° 39'8.95" W), 8 Jul 2014, J., L., A., and R. Singhurst 20,825 (BAYLU, OKL); Jct. of OK Hwy 3 and Indian Nation Turnpike , in hillside bog in right of way on NE corner inside cloverleaf adjacent to turnpike pay facility (34° 14'14.72" N, 95° 39'1.26" W), 9 Aug 2014, J., L., A., and R. Singhurst 20,826 (BAYLU, OKL). Figures 1 and 2. Singhurst, Buthod, & Holmes:Pluchea foetida in Oklahoma 2 Figure 1. Photo of capitula of Pluchea foetida in Pushmataha Co., Oklahoma. Photo by Jason Singhurst. Figure 2. Habitat photo of Pluchea foetida in hillside bog in Pushmataha Co., Oklahoma. Photo by Jas on Singhurst. Singhurst, Buthod, & Holmes:Pluchea foetida in Oklahoma 3 The nearest documented occurrences to the reported Oklahoma Pluchea foetida records include the following: (1) Miller Co., Arkansas, Reid 1511, UARK, which is approximately 215 km at 123 ̊ from the Oklahoma locations, and (2) Smithland in Mar ion Co., Texas, Singhurst & Adams 18934, BAYLU, which is about 250 km at 145 ̊ from the Oklahoma station s. The cited Oklahoma occurrences apparently represent the northwestern limits of the distribution of the species. In Pushmataha County, Pluchea foetida appears restricted to Oklahoma Acidic Hillside Seeps (Nature Serve 2014) surrounded by the Antlers Sand Formation. These hillside seeps are highly localized and isolated wetlands in southeast Oklahoma that include a number of disjunct West Gulf Coastal Plain flora at their northwest range limits. Dominant species of Oklahoma Acidic Hillside Seeps include Andropogon virginicus, Dichanthelium scoparium, Boehmeria cylindrica, Sphagnum spp., and Polytrichum commune. Other characteristic flora of the two hillside seeps include Baccharis halimifolia, Drosera brevifolia, Carex spp., Cyperus strigosus, Eleocharis tortilis, Eriocaulon decangulare, Eupatorium perfoliatum, E. rotundifolia, Gratiola pilosa, Hydrolea ovata, Juncus validus, Helianthus angustifolius, Lycopodiella appressa, Ludwigia hirtella, Mitreola petiolata, Osmunda cinnamomea, O. regalis, Oxypolis rigidior, Rhexia mariana, R. virginica, Rhynchospora caduca, R. gracilenta, R. rariflora, Rubus argutus, Scleria sp., Utricularia juncea, U. rariflora, U. subulata, Xyris difformis, and X. jupicai. Pluchea foetida will be ranked S1 by the Oklahoma Natural Heritage Inventory, indicating that it is “critically imperiled in the state because of extreme rarity or because of some factor(s) such as very steep declines in populations making it especially vulnerable to extirpation from the jurisdiction” (Oklahoma Natural Heritage Inventory 2014; Nature Serve Explorer 2014). ACKNOWLEDGEMENTS The authors thank Guy Nesom for his encouragement and edit ing of this publication. We thank Jennifer Ogle, Collections Manager at the University of Arkansas Herbarium, and Theo Witsell, botanist with the Arkansas Natural Heritage C ommission, for providing collection information for Plushea foetida in Miller County, Arkansas. We also thank the curator s f the other herbaria cited for their assistance. LITERATURE CITED Cronquist, A. 1980. Vascular Flora of the Southeastern Unite d S ates. Vol. 1, Asteraceae. Univ. North Carolina Press, Chapel Hill. Fernald, M.L. 1950. Gray’s Manual of Botany 8 th ed. American Book Co., New York. Hoagland B.W., A.K. Buthod, I.H. Butler, P.H.C. Crawford, A.H. Udasi, W.J. Elisens, and R.J. Tyrl. 2004. Oklahoma Vascular Plants Database. Oklahoma Biological Survey, Univ of Oklahoma, Norman. Kartesz, J.T. 2014. Taxonomic Data Center. The Biota of North America Program (BONAP). Chapel Hill, North Carolina. NatureServe. 2014. NatureServe Explorer: An online encyclope dia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Accessed 22 September 2014. Nesom, G. L. 2006. Pluchea. Pp. 482–484, in Flora of North America North of Mexico, V l. 19, Part 1. Oxford Univ. Press, New York and London. Oklahoma Natural Heritage Inventory (ONHI). 2014. Oklahoma Nat ural Heritage Inventory working list of rare Oklahoma plants. Univ. of Oklahoma, Norman. Accessed 22 September 2014. Small, J.K. 1933. Manual of the Southeastern Flora. Univ . North Carolina Press, Chapel Hill. Taylor, R.J. and C.E.S. Taylor. 1994. An Annotated List of Ferns, Fern Allies, Gymnosperms, and Flowering Plants of Oklahoma. Southeastern Oklahoma State Univ ., Durant. Singhurst, Buthod, & Holmes:Pluchea foetida in Oklahoma 4 Tyrl, R.J., S.C. Barber, P. Buck, W.J. Elisens, J.R. Estes, P. Folley, L.K. Magrath, C.L. Murray, A.K. Ryburn, B.A. Smith, C.E.S. Taylor, R.A. Thompson, J.B. W alker and L.E. Watson. 2010. Keys and Descriptions for the Vascular Plants of Oklahoma. Flora Oklahoma Incorporated, Noble, Oklahoma. USDA, NRCS. 2014. The PLANTS Database. National Plant D ata Team. Greensboro, North Carolina. Accessed 22 September 2014. Waterfall, U.T. 1966. Keys to the Flora of Oklahoma. D epartment of Botany and the Research Foundation. Oklahoma State Univ., Stillwater.

Euphorbia commutata has occasionally been mentioned as occurring in Texas, yet until now has remained undocumented. Recent field studies have resul ted in the discovery of a population and collection of a specimen of the species in Red River Coun ty of northeast Texas, thus verifying its occurrence in the state. A review of pertinent literatur e, description of the site of occurrence, and photographs of the natural habitat, the species, and the ca runculate seeds are included.

Andropogen glaucopsis, purple bluestem or coastal bluestem, is documented by t wo collections as occurring in southeastern Texas at the west ernmost extension of its range.

The occurrence of Selenia aurea in Texas is fully documented. The species is thus consi dered a part of the flora of Texas, at least in a historical se nse. Photographs of documenting specimens, circumstances involving the time and place of collection, and c ommentary on the history of the species in the state are included.

Sporobolus junceus, Piney Woods dropseed, a native of the contiguous southeaste rn states from Virginia to Texas, has been discovered in Oklahoma in s ndhills bordering the Harrison/Doshier Bog in Pushmataha County.