The Tamaulipan mezquital ( es, Mezquital Tamaulipeco) is a

deserts and xeric shrublands Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (ancient Greek xērós, “dry") shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this h ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

in the southern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

and northeastern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. It covers an area of , encompassing a portion of the

Gulf Coastal Plain The Gulf Coastal Plain extends around the Gulf of Mexico in the Southern United States and eastern Mexico. This coastal plain reaches from the Florida Panhandle, southwest Georgia, the southern two-thirds of Alabama, over most of Mississippi, wes ...

in southern

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

, northern

Tamaulipas Tamaulipas (), officially the Free and Sovereign State of Tamaulipas ( es, Estado Libre y Soberano de Tamaulipas), is a state in the northeast region of Mexico; one of the 31 states which, along with Mexico City, comprise the 32 Federal Entiti ...

, northeastern Coahuila, and part of Nuevo León.

Distribution

The Sierra Madre Oriental range to the west separates the Tamaulipan mezquital from the drier

Chihuahuan Desert The Chihuahuan Desert ( es, Desierto de Chihuahua, ) is a desert ecoregion designation covering parts of northern Mexico and the southwestern United States. It occupies much of far West Texas, the middle to lower Rio Grande Valley and the lo ...

. The

Tamaulipan matorral The Tamaulipan matorral is an ecoregion in the deserts and xeric shrublands biome on the eastern slopes of the Sierra Madre Oriental range in northeastern Mexico. It is a transitional ecoregion between the Tamaulipan mezquital and the Sierra Mad ...

is a transitional ecoregion between the mezquital and the

Sierra Madre Oriental pine-oak forests Sierra (Spanish for "mountain range" and " saw", from Latin '' serra'') may refer to the following: Places Mountains and mountain ranges * Sierra de Juárez, a mountain range in Baja California, Mexico * Sierra de las Nieves, a mountain range ...

to the west and the

Veracruz moist forests The Veracruz moist forests ( es, Bosques húmedos de Veracruz) is a tropical moist broadleaf forests ecoregion in eastern Mexico. Geography The Veracruz moist forests cover an area of , occupying a portion of Mexico's Gulf Coastal Plain betwee ...

to the south. The

Western Gulf coastal grasslands The Western Gulf coastal grasslands ( es, Pastizales costeros del Golfo Occidental) are a subtropical grassland ecoregion of the southern United States and northeastern Mexico. It is known in Louisiana as the "Cajun Prairie", Texas as "Coastal ...

, known as the Tamaulipan pastizal south of the border, fringe the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...

. The

Edwards Plateau The Edwards Plateau is a geographic region at the crossroads of Central Texas, Central, South Texas, South, and West Texas. It is bounded by the Balcones Fault to the south and east, the Llano Uplift and the Llano Estacado to the north, and the ...

savannas lie to the north, and the

East Central Texas forests The East Central Texas forests (33) is a small temperate broadleaf and mixed forests ecoregion almost entirely within the state of Texas, United States. The northern forests perimeter is partially within the southeast Oklahoma border. Descriptio ...

and Texas blackland prairies to the northeast.

Geography

The Bordas Escarpment transects this ecoregion, running from near the southern limit northwest to the vicinity of

Rio Grande City, Texas Rio Grande City is a city in and the county seat of Starr County, Texas. The population was 14,411 at the time of the 2020 census. The city is west of McAllen. The city also holds the March record high for the United States at . The city is c ...

, arching back northeast to the vicinity of Choke Canyon Reservoir in Texas. The region east of the Bordas Escarpment is flat with deep, sandy soils, of which vast areas both north and south of the border have been converted to agricultural use. West of the Bordas Escarpment the topography changes to gently rolling hills with a thin layer of high calcium soil over a thick layer of

caliche Caliche () is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semiarid regions ...

. Some large portions of the west are poorly suited for cultivation but good for ranching and excellent wildlife habitat.Fulbright, Timothy E., and Fred C. Bryant (2004).The Last Great Habitat. A Special Publication of the Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville. Special Publication No. 1, 1-32 pp. A series of Cenozoic strata of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates ...

, siltstone, and claystone occur throughout most of the region. These strata are slightly tilted, gently slanting seaward, with increasingly recent exposures to the east, including some Quaternary bodies at the coast transitioning into the sea, and a few older

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

exposures and outcrops appearing in some far western interior areas. Elevations generally range from near sea level to 300 meters, transitioning at ca. 300–500 meters into the Sierra Madres,

, and

Chihuahua Desert Chihuahua may refer to: Places *Chihuahua (state), a Mexican state **Chihuahua (dog), a breed of dog named after the state **Chihuahua cheese, a type of cheese originating in the state **Chihuahua City, the capital city of the state ** Chihuahua Mu ...

in western areas. A series of small mountain ranges occur in the region, isolated on the coastal plain between the Sierra Madre Oriental and the Gulf of Mexico. These ranges are not part of the strata of the Gulf Coast Plain or the complexly folded and faulted

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

and

formations of the Sierra Madre Oriental. The Sierra de San Carlos, (and Sierra de Tamaulipas just beyond the southern limit of this ecoregion) are

plutons In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma o ...

intrusions of

nepheline syenite Nepheline syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are al ...

to gabbroic composition, emplaced during the Mid-

Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

with a few minor sierras of alkaline basalt flows occurring locally (e.g. in the vicinity of

Llera, Tamaulipas Llera is a municipality located in the Mexican state of Tamaulipas Tamaulipas (), officially the Free and Sovereign State of Tamaulipas ( es, Estado Libre y Soberano de Tamaulipas), is a state in the northeast region of Mexico; one of the 31 ...

).Ferrusquía-Villafranca, Ismael. 1993. ''Geology of Mexico: A Synopsis'', pages 3-107. In. T. P. Ramamoorthy, Robert Bye, Antonio Lot, and John Fa (Eds.). ''Biological Diversity of Mexico: Origins and Distribution.'' Oxford University Press, Inc. New York. The Coastal Sand Plain, sometimes referred to as the "Wild Horse Desert", is a region of Quaternary sand deposits extending about 60 miles inland from the

Laguna Madre The Laguna Madre is a long, shallow, hypersaline lagoon along the western coast of the Gulf of Mexico in Nueces, Kenedy, Kleberg, Willacy and Cameron Counties in Texas, United States. It is one of seven major estuaries along the Gulf Coast ...

. It is bordered by Baffin Bay to the north and the Lower Rio Grande Valley to the south. Quaternary to Tertiary marine sedimentary strata, which may be exposed in western areas, underlie the sand sheet. The sand sheet is six feet deep in many places with maximum dune elevations reaching 30 feet. Although the area is generally flat, the unstable sands often form a dune and

swale Swale or Swales may refer to: Topography * Swale (landform), a low tract of land ** Bioswale, landform designed to remove silt and pollution ** Swales, found in the formation of Hummocky cross-stratification Geography * River Swale, in North ...

topography where vegetated dunes are interspersed with active, unstable, wind-blow dunes. The active dunes attain areas as large as 250 acres, predominantly in the eastern third. Grasslands cover much of the sand plain where seacoast bluestem ('' Schizachyrium littorale'') is dominant in all but the wettest areas. These grasslands are banded with live oak (''

Quercus virginiana ''Quercus virginiana'', also known as the southern live oak, is an evergreen oak tree endemic to the Southeastern United States. Though many other species are loosely called live oak, the southern live oak is particularly iconic of the Old Sou ...

'') groves, forming dense forest in spots, and smaller honey mesquite (''

Prosopis glandulosa ''Prosopis glandulosa'', commonly known as honey mesquite, is a species of small to medium-sized, thorny shrub or tree in the legume family (Fabaceae). Distribution The plant is primarily native to the Southwestern United States and Northern M ...

'') mottes in discontinuous belts which are sometimes connected with one another and collectively cover at least a quarter of the sand sheet. Numerous ephemeral, internally drained ponds form where subsidence and blow-outs occur.Fuibright, Timothy E., David D. Diamond, John Rappoie, and Jim Norwine. 1990. Coastal Sand Plain of Southern Texas. Rangelands 12(6): 337-340. Hydrology: The region is generally semi-arid however, various wetlands are present. The

is one of only five hypersaline coastal lagoons (or negative estuaries) in the world and a significant

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

in itself, laying between the Gulf of Mexico and the Tamaulipan mezquital ecoregion.Tunnell, Jr. John W. and Frank W. Judd. editors. (2002). The Laguna Madre of Texas and Tamaulipas. Texas A&M University Press, College Station, Texas. xxi, 346 pp. As one moves inland from the hypersaline lagoon, a relatively narrow band of freshwater marshlands are encountered running north to south, albeit occurring fragmented and irregularly. These marshes are dynamic, fluctuating with rainfall and tropical storm activity, and alternating with wet and dry periods. When and where present, these marshlands can be locally, surprisingly extensive with deep marshes and both permanent and ephemeral freshwater ponds that support populations of salamanders (''

Sirens Siren or sirens may refer to: Common meanings * Siren (alarm), a loud acoustic alarm used to alert people to emergencies * Siren (mythology), an enchanting but dangerous monster in Greek mythology Places * Siren (town), Wisconsin * Siren, Wisco ...

''), turtles (''

Trachemys ''Trachemys'' is a genus of turtles belonging to the family Emydidae. Members of this genus are native to the Americas, ranging from the Midwestern United States south to northern Argentina, but one subspecies, the red-eared slider (''T. script ...

''), and millions of migrating

waterfowl Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which i ...

, such as redheads ('' Aythya americana'') in the winter.Smith, Elizabeth H. (2002). Redheads and Other Wintering Waterfowl. 169-181 pp. In Tunnell, Jr. John W. and Frank W. Judd. (editors). ''The Laguna Madre of Texas and Tamaulipas''. Texas A&M University Press, College Station, Texas. xxi, 346 pp. Farr, William L. (2015). Herpetofauna of Tamaulipas. 101-121 pp. In. Lemos Espinal, J. A. (Editor). ''Amphibians and Reptiles of the US-Border States''. Texas A&M University Press. College Station, Texas. x, 614 pp. Several rivers cross the region, all flowing eastward to the

. Many of these river have created innumerable

oxbow lakes An oxbow lake is a U-shaped lake or pool that forms when a wide meander of a river is cut off, creating a free-standing body of water. In South Texas, oxbows left by the Rio Grande are called '' resacas''. In Australia, oxbow lakes are calle ...

, resacas, and abandoned channels with associated marshes and swamps as they meander across the flat coastal plain east of the Bordas Escarpment. The few remaining

riparian zones A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...

in this region that have not been cleared for agriculture, housing, and industry, can support unexpectedly lush tropical jungle vegetation, particularly in the south. The

San Antonio River The San Antonio River is a major waterway that originates in central Texas in a cluster of springs in midtown San Antonio, about 4 miles north of downtown, and follows a roughly southeastern path through the state. It eventually feeds into the ...

(a major tributary of the Guadalupe River) runs at the approximate northeastern border of this region. Other major rivers (north to south) include: the

Nueces River The Nueces River is a river in the U.S. state of Texas, about long. It drains a region in central and southern Texas southeastward into the Gulf of Mexico. It is the southernmost major river in Texas northeast of the Rio Grande. ''Nueces'' ...

and its tributary the Frio River; Rio Grande (referred to as Rio Bravo in Mexico) and its tributaries Rio Salado, Rio San Juan; the Rio San Fernando (sometimes called the Rio Conchos and not to be confused with the major drainage Rio Conchos of Chihuahua); the Rio Soto La Marina and its tributaries Rio San Carlos, Rio Pilón, San Antonio, Rio Purificacion, Rio Corona, Rio Santa Ana, form the approximate southern border.Texas Water Development Board, TWDB Maps:
Major Surface Water Features
'.Agustin Palacios Roji Grcía and Joaquin Palacios Roji Grcía. (2007). Por Las Carreteras de México. Guia Roji, S.A. de C. V. México, D. F., Mexico. 151 pp. A number of large lakes occur in the region, but they were all constructed in the decades fallowing the Second World War in the 20th century. These include: Choke Canyon Reservoir and

Lake Corpus Christi Lake Corpus Christi is a reservoir in coastal southern Texas. The lake was created by impoundment of the Nueces River by the Wesley E. Seale Dam opened in 1958. The lake and the dam that creates it are managed by the City of Corpus Christi. Lak ...

in the Nueces River drainage in the USA; Amistad International Reservoir and

Falcon International Reservoir Falcon International Reservoir ( es, Embalse Internacional Falcón), commonly called Falcon Lake, is a reservoir on the Rio Grande 40 miles (64 km) southeast of Laredo, Texas, United States, and Nuevo Laredo, Tamaulipas, Mexico. The huge lake ...

on the Rio Grande; Presa Venustiano Carranza in Coahuila on the Rio Salado, Presa El Cuchillo in Nuevo Leon and Presa Marte R. Gómez in Tamaulipas on the Rio San Juan, and Presa Vicente Guerrero in Tamaulipas on the Rio Soto La Marina drainage in Mexico.

Tamaulipan mezquital gallery

File:Wild Olive (Cordia boissieri), FM 1017, Jim Hogg County, Texas, USA (10 April 2016).jpg, Grasslands with Wild Olive (''

Cordia boissieri ''Cordia boissieri'' is a white-flowered, evergreen shrub or small tree in the borage family (Boraginaceae). Its native range extends from southern Texas in the United States south to central Mexico. Common names include anacahuita, Mexican olive ...

''), Jim Hogg County, Texas, USA (10 April 2016) File:Sabal Palm Sanctuary, Cameron Co. TX, 11 April 2016.jpg, Mesquite woodlands, Sabal Palm Sanctuary, Cameron County Texas (11 April 2016). File:Bentsen-Rio Grande Valley State Park, Hidalgo County, Texas, USA (15 April 2016).jpg, Bentsen-Rio Grande Valley State Park, Hidalgo County, Texas, USA (15 April 2016) File:State Highway 16, Duval County, Texas, USA. (16 April 2016).jpg, State Highway 16, Duval County, Texas, USA. (16 April 2016) File:Tamaulipan thornscrub habitat, private ranchland, Webb Co. TX; 10 June 2016.jpg, Tamaulipan thornscrub, private ranchland, Webb County, Texas (10 June 2016). File:Sabal Palm Sanctuary, Cameron Co. TX; 11 Apr 2016.jpg, Old growth sabal palm grove, Sabal Palm Sanctuary, Cameron County, Texas, USA (11 April 2016). File:Tamaulipan thornscrub, State Highway 4, Cameron Cameron County, Texas, USA (11 April 2016).jpg, Tamaulipan thornscrub, State Highway 4, Cameron Cameron County, Texas, USA (11 April 2016) File:Trail in Santa Ana National Wildlife Refuge, Hidalgo County, Texas, USA (14 April 2016).jpg, Trail through mature thornscrub forest in

Santa Ana National Wildlife Refuge Santa Ana National Wildlife Refuge is a National Wildlife Refuge situated along the banks of the Rio Grande, south of Alamo in the Lower Rio Grande Valley, in Hidalgo County, South Texas. The wildlife refuge was established for the protect ...

, Hidalgo County, Texas, USA (14 April 2016). File:Yturria Brush National Wildlife Refuge, Hidalgo County, Texas, USA (15 April 2016).jpg, Road in thornscrub vegetation, Yturria Brush National Wildlife Refuge, Hidalgo County, Texas, USA (15 April 2016) File:Rio Grande SE of Falcon Reservoir, Municipality of Mier, Tamaulipas, Mexico (12 August 2007).jpg, Rio Grande southeast of Falcon Reservoir, Municipality of Mier, Tamaulipas, Mexico (12 August 2007) File:Thornscrub south of Reynosa, Municipality of Reynosa, Tamaulipas, Mexico (13 August 2007).jpg, Thornscrub south of Reynosa, Municipality of Reynosa, Tamaulipas, Mexico (13 August 2007) File:Sierra San Carlos, Municipality of San Carlos, Tamaulipas, Mexico (14 July 2007).jpg, Sierra San Carlos, Municipality of San Carlos, Tamaulipas, Mexico (14 July 2007) File:Sierra San Carlos, with Pinus teocote (left), Municipality of San Carlos, Tamaulipas, Mexico (12 July 2007).jpg, Sierra San Carlos, with a pine tree ('' Pinus teocote'') on left, Municipality of San Carlos, Tamaulipas, Mexico (12 July 2007) File:Thornscrub ranchland west of Tepehuajes, Municipio Soto La Marina, Tamaulipas, Mexico (20 May 2002).jpg, Thornscrub ranchland west of Tepehuajes, Municipio Soto La Marina, Tamaulipas, Mexico (20 May 2002)

Flora

This semi-arid region is dominated by Mezquital (Spanish for a mesquite groveGooch, Anthony, and Angel García de Paredes. 1978. ''Cassell's Spanish-English Dictionary''. Cassell Ltd. London and Macmillan Publishing Co. Inc. New York. xxv, 1109 pp. ), thorny brush, and chaparral vegetation referred to as Tamaulipan thornscrub. In this subtropical environment some plant growth continues through most of the year, particularly in the south. Years with droughts or tropical storms and hurricanes can dramatically affect vegetation at any given locality, particularly the herbaceous ground layer, which may be sparse with patches of bare earth in a dry year, or thick and verdant in a wet year. Thornscrub vegetation tends to grow taller and thicker in the east, benefited by coastal moisture where it can be impenetrable in places, and it is often shorter and more open in interior areas of the region, although soils also influence this throughout the region.Blair, W. Frank. (1950). ''The Biotic Provinces of Texas''. Texas Journal of Science. 2(1): 93-117.Martin, Paul S., C. Richard Robins, and William B. Heed. 1954. ''Birds and Biogeography of the Sierra de Tamaulipas, an Isolated Pine-Oak Habitat''.The Wilson Bulletin.Vol. 66, No. 1: 38-57. Mixtures of sand and clay make up much of the soils with pockets of near pure sand and near pure clay occurring locally.Richardson, Alfred and Ken King. 2011. ''Plants of Deep South Texas, A Field Guide to the Woody and Flowering Species''. Texas A&M University Press. College Station, Texas. xii, 457 pp. Sandy soils in this region tend to support more open vegetation with widely spaced trees and shrubs in grasslands, while clay soils tend to support a greater diversity and denser, sometimes even canopied areas of trees and shrubs. Past land usage can also have a significant influence, where recently cleared areas may have a near monoculture of honey mesquite (''

''), with pricklypear (''

Opuntia engelmannii ''Opuntia engelmannii'' is a prickly pear common across the south-central and Southwestern United States and northern Mexico. It goes by a variety of common names, including desert prickly pear, discus prickly pear, Engelmann's prickly pear in ...

'' var. ''lindheimeri''), and non-native grasses in the understory.Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Savanna Grassland
' (Accessed: 18 August 2020). Some species of are nearly ubiquitous, occurring in most of the soils and vegetation communities, although varying in levels of dominance, some of these include honey mesquite (''

''), spiny hackberry (''

Celtis ehrenbergiana ''Celtis ehrenbergiana'', called the desert hackberry or spiny hackberry, is a plant species that has long been called ''C. pallida'' by many authors, including in the "Flora of North America" database. It is native to Arizona, Florida, New Mexic ...

''), desert Christmas cholla ('' Cylindropuntia leptocaulis''), Texas persimmon ('' Diospyros texana''), Texas prickly pear (''

'' var. ''lindheimeri''), and black brush ('' Vachellia rigidula''). Other common trees and shrubs more often found on clay soils include white bush ('' Aloysia gratissima''), goat bush (''

Castela erecta ''Castela'' is a genus of thorny shrubs and small trees in the family Simaroubaceae. Members of the genus are native to the Americas, especially the tropical regions. The generic name honours the French naturalist René Richard Louis Castel. '' ...

''), brasil (''

Condalia hookeri ''Condalia'' is a genus of spiny shrubs in the tribe Rhamneae of the buckthorn family, Rhamnaceae. It was named for Antonio Condal, an 18th Spanish physician. Members of the genus are native to tropical and subtropical deserts and xeric shru ...

''), knackaway (''

Ehretia anacua ''Ehretia anacua'' is medium-sized tree found in eastern Mexico and southern Texas in the United States. It is a member of the borage family, Boraginaceae. One of its common names, anacua, is derived from the Mexican Spanish word ''anacahuite'', ...

''). Texas lignum-vitae (''

Guaiacum angustifolium ''Guaiacum angustifolium'' is a species of flowering plant in the caltrop Family (biology), family, Zygophyllaceae. Common names include Texas guaiacum, Texas lignum-vitae, soapbush and huayacán. It is native to southern and western Texas in the ...

''), Texas purple sage ('' Leucophyllum frutescens''), retama (''

Parkinsonia aculeata ''Parkinsonia aculeata'' is a species of perennial flowering tree in the pea family, Fabaceae. Common names include palo verde, Mexican palo verde, Parkinsonia, Jerusalem thorn, jelly bean tree, palo de rayo, and retama. Etymology The genus name ...

''), Berlandier acacia (''

Senegalia berlandieri ''Senegalia berlandieri'' (Berlandier acacia, guajillo acacia, guajillo, huajillo, huajilla) is a shrub native to the Southwestern United States and northeast Mexico that belongs to the Mimosoid clade of Fabaceae. It grows tall, with blossoms ...

''), and huisache (''

Vachellia farnesiana ''Vachellia farnesiana'', also known as ''Acacia farnesiana'', and previously ''Mimosa farnesiana'', commonly known as sweet acacia, huisache, or needle bush, is a species of shrub or small tree in the legume family, Fabaceae. Its flowers are u ...

'' var. ''farnesiana'').Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Calcareous Thornscrub
' (Accessed: 18 August 2020). Grasslands with sparsely scattered trees and shrubs occur on level to gently rolling sites with sandy soils. These are dominated by dense graminoids such as Texas grama ('' Bouteloua rigidiseta''), little bluestem (''

Schizachyrium scoparium ''Schizachyrium scoparium'', commonly known as little bluestem or beard grass, is a species of North American prairie grass native to most of the contiguous United States (except California, Nevada, and Oregon) as well as a small area north of ...

''), sand dropseed ('' Sporobolus cryptandrus''), and many others. Wildflowers include bull-nettle (''

Cnidoscolus texanus ''Cnidoscolus texanus'', commonly known as Texas bullnettle (also Texas bull nettleNieland, Lashara J. and Willa F. Finley (2009) Lone Star Wildflowers: A Guide to Texas Flowering Plants. Texas Tech University Press. Lubbock, Texas x, 320 pp. an ...

''), shrubby blue sage ('' Salvia ballotiflora''), hairy tubetongue ('' Justicia pilosella''), Texas palafoxia ('' Palafoxia texana''), and hairy zexmania ('' Wedelia texana''). Shrub-dominated patches may develop within these grassy sites where tighter, clay soils occur, reaching six meters or higher, often dominated by several of the ubiquitous species noted above. Woodlands occur in places with a well-developed canopy over an understory of grasses. The grasses in these communities contain a layer of taller species such as hooded windmill grass (''

Chloris cucullata ''Chloris cucullata'' is a species of grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natur ...

'') and four-flower trichloris (''

Trichloris pluriflora ''Trichloris'' is a genus of New World plants in the grass family. ; Species * ''Trichloris crinita'' (Lag.) Parodi - United States (Arizona, New Mexico, Texas), northern Mexico ( Baja California Sur, Sonora, Chihuahua, Durango, Coahuila, ...

''), and a layer of shorter species such as grama (''

Bouteloua ''Bouteloua'' is a genus of plants in the grass family. Members of the genus are commonly known as grama grass. Taxonomy and systematics The genus was named for Claudio and Esteban Boutelou, 19th-century Spanish botanists. David Griffiths ...

'' spp.) and curly mesquite grass ('' Hilaria belangeri''). In some places dense stands of Texas prickly pear occur instead of shrubs and grasses. Canopy species include many ubiquitous trees along with huisache (''

Acacia farnesiana ''Vachellia farnesiana'', also known as ''Acacia farnesiana'', and previously ''Mimosa farnesiana'', commonly known as sweet acacia, huisache, or needle bush, is a species of shrub or small tree in the legume family, Fabaceae. Its flowers are use ...

''), desert hackberry ('' Celtis pallida''), brasil (''

''), Texas hogplum ('' Colubrina texensis''), Colima (''

Zanthoxylum fagara ''Zanthoxylum fagara'' or wild lime, is a species of flowering plant that—despite its name—is not part of the genus ''Citrus'' with real limes and other fruit, but is a close cousin in the larger citrus family, Rutaceae. It is native to sout ...

''), and others. Other shrubs include desert yaupon ('' Schaefferia cuneifolia''), desert olive ('' Forestiera angustifolia''), and lotebush ('' Ziziphus obtusifolia''). Xeric rocky uplands with shallow calcareous soils on

and gravel substrates support shrublands one half to two meters high. Species such as cenizo ('' Leucophyllum frutescens''), guajillo (''

Acacia berlandieri ''Senegalia berlandieri'' (Berlandier acacia, guajillo acacia, guajillo, huajillo, huajilla) is a shrub native to the Southwestern United States and northeast Mexico that belongs to the Mimosoid clade of Fabaceae. It grows tall, with blosso ...

''), Texas kidneywood ('' Eysenhardtia texana''), twisted acacia ('' Vachellia schaffneri''), Spanish dagger ('' Yucca treculeana''), and baretta ('' Helietta parvifolia'') and others grow with ubiquitous trees and shrubs. The creosote bush (''

Larrea tridentata ''Larrea tridentata'', called creosote bush and greasewood as a plant, chaparral as a medicinal herb, and ''gobernadora'' (Spanish for "governess") in Mexico, due to its ability to secure more water by inhibiting the growth of nearby plants. In S ...

'') grows in western areas. The herbaceous layer may be sparse in places where rocky exposures occur. Forbs and wildflowers can be conspicuous in rocky areas, including narrowleaf thryallis ('' Galphimia angustifolia''), peonia (''

Acourtia runcinata ''Acourtia runcinata'', the featherleaf desertpeony or desert paeonia, is a North American species of plant in the family Asteraceae. It is native to northern Mexico (Chihuahua, Coahuila, Hidalgo, Nuevo León, San Luis Potosí, Tamaulipas) and al ...

''), Gregg's senna ('' Chamaecrista greggii''), plateau rocktrumpet ('' Macrosiphonia macrosiphon''), and hairy zexmania ('' Wedelia hispida'').Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Mixed Deciduous Thornscrub
' (Accessed: 18 August 2020). Saline lakes and saline thornscrub occur in some interior, low-lying areas with interior draining basins, created by runoff and evaporation. Lakebeds (often dry) may lack vegetation or have sparse

halophytic A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs and seashores. ...

grasses and forbs like alkali sacaton (''

Sporobolus airoides ''Sporobolus airoides'' is a species of grass known by the common name alkali sacaton. It is native to western North America, including the Western United States west of the Mississippi River, British Columbia and Alberta in Canada, and northern ...

''), sea ox-eye daisy ('' Borrichia frutescens''), and saltwort ('' Batis maritima''). Surrounding saline thornscrub is semi-open with ubiquitous shrubs under 5 m., growing with species like saladillo ('' Varilla texana''), knifeleaf condalia ('' Condalia spathulata''), Johnston's seaheath ('' Frankenia johnstonii''), and screw bean mesquite (''

Prosopis reptans ''Prosopis'' is a genus of flowering plants in the family Fabaceae. It contains around 45 species of spiny trees and shrubs found in subtropical and tropical regions of the Americas, Africa, Western Asia, and South Asia. They often thrive in ...

'') among others. Soils may have a thin layer of gravel over clay with patchy grasses and cacti such as Fitch's hedgehog cactus (''

Echinocereus reichenbachii ''Echinocereus reichenbachii'' (commonly known as lace or hedgehog cactus) is a perennial plant and shrub in the cactus family. The species is native to the Chihuahuan Desert and parts of northern Mexico and the southern United States, where ...

'' var. ''fitchii'') and horse crippler (''

Echinocactus texensis ''Echinocactus texensis'' (also known as the horse crippler or devil's pincushion) is a cactus in the subfamily Cactoideae. It is endemic to the United States and Mexico. It has one synonym A synonym is a word, morpheme, or phrase that mean ...

'').Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Saline Lake
' (Accessed: 18 August 2020).Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Saline Thornscrub
' (Accessed: 18 August 2020).Cram, Silke, Irene Sommer, Luis-Miguel Morales, Oralia Oropeza, Estela Carmona, and Francisco Gonzalez-Medrano. 2006. ''Suitability of the vegetation types in Mexico's Tamaulipas state for the siting of hazardous waste treatment plants''. Journal of Environmental Management. 80 (2006): 13-24. Internally drained basins with non-salin, or freshwater also occur on clay lined or clay loam soils that hinder drainage. Sometimes called potholes, lagunas, lagunitas, ponds, or copitas, these are ephemeral wetlands but may remain moist over extended periods of time.Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Closed Depression Wetland
' (Accessed: 18 August 2020). Riparian zones and floodplains can support luxuriant forest on the

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. All ...

soils of the major rivers. These can sometimes have a dense canopy up to 15 meters high. Dominant canopy species may include many of the ubiquitous and common species noted above, as well as granjeno (''

''), sugar hackberry (''

Celtis laevigata ''Celtis laevigata'' is a medium-sized tree native to North America. Common names include sugarberry, Southern hackberry, or in the southern U.S. sugar hackberry or just hackberry. Sugarberry is easily confused with common hackberry ('' C. oc ...

''), Texas ebony (''

Ebenopsis ebano ''Ebenopsis ebano'' is a species of flowering plant in the family Fabaceae, that is native to the coastal plain of southern Texas in the United States and eastern Mexico. It is commonly known as Texas ebony or ''ebano'' (in Spanish). Descriptio ...

''), anacua (''

''), Mexican ash ('' Fraxinus berlandierana''), tepeguaje ('' Leucaena pulverulenta''), and cedar elm (''

Ulmus crassifolia ''Ulmus crassifolia'' Nutt., the Texas cedar elm or simply cedar elm, is a deciduous tree native to south-central North America, mainly in southern and eastern Texas, southern Oklahoma, Arkansas, and Louisiana, with small populations in weste ...

''). Riverbanks may have a reduced over-story with black mimosa ('' Mimosa asperata''), black willow (''

Salix nigra ''Salix nigra'', the black willow, is a species of willow native to eastern North America, from New Brunswick and southern Ontario west to Minnesota, and south to northern Florida and Texas. Description ''Salix nigra'' is a medium-sized decid ...

''), and giant reed (''

Arundo donax ''Arundo donax'' is a tall perennial cane. It is one of several so-called reed species. It has several common names including giant cane, elephant grass, carrizo, arundo, Spanish cane, Colorado river reed, wild cane, and giant reed. ''Arundo'' a ...

'') an invasive species. Numerous species of vines and epiphytes like Spanish moss (''

Tillandsia usneoides Spanish moss (''Tillandsia usneoides'') is an epiphytic flowering plant that often grows upon large trees in tropical and subtropical climates. It is native to much of Mexico, Bermuda, the Bahamas, Central America, South America, the Southern Un ...

'') are frequently encountered as well as rarer Bailey's ballmoss (''

Tillandsia baileyi ''Tillandsia baileyi'', commonly known as the reflexed airplant or Bailey's ball moss, is a species of bromeliad that is native to southern Texas in the United States and Tamaulipas in Mexico. It is found along the Gulf of Mexico from Kingsvill ...

''). The herbaceous layer is often not well developed. In the

drainage and northward, pecan ('' Carya illinoinensis'') and plateau live oak (''

Quercus fusiformis ''Quercus fusiformis'' (also often referred to as ''Q. virginiana'' var. ''fusiformis''), commonly known as escarpment live oak, plateau live oak, plateau oak, or Texas live oak, is an evergreen or nearly evergreen tree. Its native range inc ...

'') may be common. Diversity increases southward and the Rio Grande Delta has a denser understory with a sub-canopy layer at 4 to 5 meters including Sierra Madre torchwood ('' Amyris madrensis''), Texas torchwood ('' Amyris texana''), Barbados cherry (''

Malpighia glabra ''Malpighia glabra'' is a tropical fruit-bearing shrub or small tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narr ...

''), catclaw acacia ('' Senegalia wrightii''), brushholly (''

Xylosma flexuosa ''Xylosma flexuosa'', commonly known as brushholly or coronilla, is a species of flowering plant in the family Salicaceae, that is native to southern North America and northern South America. Its range stretches from southern Texas in the United ...

''), and others. Monumental Montezuma cypresses (''

Taxodium mucronatum ''Taxodium mucronatum'', commonly known as Montezuma bald cypress, Montezuma cypress, or ahuehuete, is a species of '' Taxodium'' that is primarily native to Mexico and Guatemala, with a few populations in the southwestern United States. Ahuehue ...

'') once lined portions of the Rio Grande and other southern rivers, but few remain today. Parque Nacional El Sabinal in the town of Ciudad Cerraivo, Nuevo Leon preserves some fine examples of old Montezuma cypress in an urban environment.Gobierno El México
Parque Nacional El Sabinal
/ref> Only a few, small groves of Mexican sabal palm (''

Sabal mexicana ''Sabal mexicana'' is a species of palm tree that is native to far southern North America. Common names include Rio Grande palmetto, Mexican palmetto, Texas palmetto, Texas sabal palm, palmetto cabbage and palma de mícharos. The specific epi ...

'') remain on the Rio Grande Delta, but it is believed they once occurred as far as 120 km. inland. Palms may dominate the canopy or share dominance with other floodplain species reaching 15 meters. The herbaceous layer may include bunch cutgrass ('' Leersia monandra''), tropical sage (''

Salvia coccinea ''Salvia coccinea'', the blood sage, scarlet sage, Texas sage, or tropical sage, is a herbaceous perennial in the family Lamiaceae that is widespread throughout the Southeastern United States, Mexico, Central America, the Caribbean, and northern ...

''), and blue boneset ('' Tamaulipa azurea''), or dead palm fronds may restrict the development of the ground layer.Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Floodplain
' (Accessed: 18 August 2020).Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Rio Grande Delta Thorn Woodland and Shrubland
' (Accessed: 18 August 2020).Texas Parks and Wildlife (& Nature Serve Explorer), Ecological Mapping Systems of Texas:
Tamaulipan Palm Grove Riparian Forest
' (Accessed: 18 August 2020). Cacti: This region is rich in cacti diversity. In addition to wide-ranging species like lace cactus ('' Echinocactus reichenbachii''), and horse-crippler cactus (''

''), other species found in the province include: root cactus ('' Sclerocactus'' ''Acanthocereus''''scheeri''), triangle or barbed wire cactus ('' Acanthocereus tetragonus''), star cactus (''

Astrophytum asterias ''Astrophytum asterias'' is a species of cactus in the genus '' Astrophytum'', and is native to small parts of Texas in the United States and Mexico. Common names include sand dollar cactus, sea urchin cactus, star cactus and star peyote. Desc ...

''), Runyon's beehive cactus ('' Coryphantha macromeris'' var. ''runyonii''), Berlandier's hedgehog (''

Echinocereus berlandieri ''Echinocereus berlandieri'' (Berlandier's hedgehog cactus) is a species of hedgehog cactus. Its range includes most of South Texas, and is commonly found along the Nueces River and the lower Rio Grande. References {{Taxonbar, from=Q733365 ...

''), pitaya (''

Echinocereus ''Echinocereus'' is a genus of ribbed, usually small to medium-sized, cylindrical shaped cacti, comprising about 70 species native to the southern United States and Mexico in very sunny, rocky places. Usually the flowers are large and the fruit ...

enneacanthus'' var. ''brevispinus''), Allicoche hedgehog cactus (''

papillosus''), ladyfinger hedgehog ('' Echinocereus pentalophus''), Dahlia cactus ('' Echinocereus poselgeri''), Junior Tom Thumb cactus (''

Escobaria ''Escobaria'', pincushion cactus or foxtail cactus is a genus of low-growing cacti that range from the southernmost parts of central and western Canada through northern Mexico, with one species in Cuba. The genus comprises about 23 species. The ...

emskoetteraana''), Turk's head barrel cactus ('' Ferocactus hamatacanthus'' var. ''sinuatus''), peyote (''

Lophophora williamsii The peyote (; ''Lophophora williamsii'' ) is a small, spineless cactus which contains psychoactive alkaloids, particularly mescaline. ''Peyote'' is a Spanish word derived from the Nahuatl (), meaning "caterpillar cocoon", from a root , "to ...

''), Heyder's pincushion cactus (''

Mammillaria heyderi ''Mammillaria heyderi'' is a species of cactus in the tribe Cacteae. It is endemic to Sonora and Chihuahua in Mexico and New Mexico, Arizona, and Texas in the United States. References External links ''Mammillaria heyderi''at Tropicos Tro ...

''), hair-covered cactus or Texas pincushion ('' Mammillaria prolifera'' var. ''texana''), pale mammillaria (''

Mammillaria sphaerica ''Mammillaria sphaerica'', the longmamma nipple cactus or pale mammillaria is a species of flowering plant in the cactus family Cactaceae, native to south eastern Texas in the USA and north eastern Mexico, where it occurs in scattered patches at ...

''), twisted rib cactus ('' Thelocactus setispinus'') and several others.Loflin, Brian and Shirley Loflin. (2009). ''Texas Cacti''. Texas A&M University Press, College Station. xv, 291. Some of these species have very limited distributions and are endemic to the region such as '' Astrophytum caput-medusae'' from Nuevo Leon, Mexico.Hernández, Héctor M. and Carlos Gómez-Hinostrosa. 2011. Mapping the Cacti of Mexico, Their geographical distribution and based on referenced records. DH Books, Milborne Port, England with CONABIO, Succulent Plant Research, Vol. 7: 128 pp.

Fauna

Mammals: This region once hosted an impressive number of carnivores but, most were very rare, or entirely

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

by the early to mid 20th century. The gray wolf (''

Canis lupus The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, and gray wolves, as popularly un ...

'') is extirpated and black bears (''

Ursus americanus Ursus is Latin for bear. It may also refer to: Animals * ''Ursus'' (mammal), a genus of bears People * Ursus of Aosta, 6th-century evangelist * Ursus of Auxerre, 6th-century bishop * Ursus of Solothurn, 3rd-century martyr * Ursus (''praefectus ...

'') are now largely restricted to the Sierra de Picachos in

Nuevo Leon Nuevo is the Spanish word for "new". It may refer to: * Nuevo, California, a town in the state of California * Nuevo (band), featuring singer and musician Peter Godwin * Nuevo (Bayamón), a settlement in Puerto Rico * "Nuevo", Spanish-language vers ...

, Mexico. The most recent records of the jaguar (''

Panthera onca The jaguar (''Panthera onca'') is a large cat species and the only living member of the genus '' Panthera'' native to the Americas. With a body length of up to and a weight of up to , it is the largest cat species in the Americas and the th ...

'') in Texas, USA are from the early 1950s, but the species still lingers, although at risk of extinction in Mexico. Similarly, jaguarondi ('' Herpailurus yaguarondi''), ocelot ('' Leopardus pardalis''), and margay (''

Leopardus wiedii The margay (''Leopardus wiedii'') is a small felidae, wild cat native to Central America, Central and South America. A solitary and nocturnal cat, it lives mainly in primary Evergreen forest, evergreen and deciduous forest. Until the 1990s, mar ...

'') are all threatened or endangered in the US and Mexico. Some puma or mountain lion (''

Puma concolor The cougar (''Puma concolor'') is a large cat native to the Americas. Its range spans from the Canadian Yukon to the southern Andes in South America and is the most widespread of any large wild terrestrial mammal in the Western Hemisphere ...

''), White-nosed coati (''

Nasua narica The white-nosed coati (''Nasua narica''), also known as the coatimundi (), is a species of coati and a member of the family Procyonidae (raccoons and their relatives). Local Spanish names for the species include ''pizote'', ''antoon'', and ''t ...

''), and American Badger ('' Taxidea taxus'') populations still persist, apparently in stable numbers in some remote areas, although the latter is considered a threatened species in Mexico. A few other species such as the Northern Raccoon (''

Procyon lotor The raccoon ( or , ''Procyon lotor''), sometimes called the common raccoon to distinguish it from other species, is a mammal native to North America. It is the largest of the procyonid family, having a body length of , and a body weight of ...

''), Coyote (''

Canis latrans The coyote (''Canis latrans'') is a species of canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecological ni ...

''), and to a lesser extent Bobcats (''

Lynx rufus The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the I ...

'') have adapted to human encroachment and development.Schmidly, D. J. (2004). ''The Mammals of Texas''. ixth Edition University of Texas Press, Austin, Texas. xviii, 501 pp. Ceballos, G. Ed. (2014). ''Mammals of Mexico''. Johns Hopkins University Press. Baltimore, Maryland. xiii, 957 pp. Other mammals found in the region include the collared peccary (''

Pecari tajacu The collared peccary (''Dicotyles tajacu'') is a species of artiodactyl (even-toed) mammal in the family Tayassuidae found in North, Central, and South America. It is the only member of the genus ''Dicotyles''. They are commonly referred to as ...

''), white-tailed deer ('' Odocoileus virginianus''), black-tailed jackrabbit (''

Lepus californicus The black-tailed jackrabbit (''Lepus californicus''), also known as the American desert hare, is a common hare of the western United States and Mexico, where it is found at elevations from sea level up to . Reaching a length around , and a ...

''), nine-banded armadillo ('' Dasypus novemcinctus''), Mexican long-tongued bat ('' Choeronycteris mexicana''), and the southern yellow bat ('' Lasiurus ega''). Rodents include the predatory northern grasshopper mouse (''

Onychomys leucogaster The northern grasshopper mouse (''Onychomys leucogaster'') is a North American carnivorous rodent of the family Cricetidae. It ranges over much of the western part of the continent, from southern Saskatchewan and central Washington to Tamaulipas ...

''), the Mexican prairie dog ('' Cynomys mexicanus''), Rio Grande ground squirrel ('' Ictidomys parvidens'') and others such as Coue's rice rat ('' Oryzomys couesi''), southern plains woodrat ('' Neotoma micropus''), Mexican spiny pocket mouse ('' Liomys irroratus''), and Merriam's pocket mouse ('' Perognathus merriami''). File:Collared peccary (Pecari tajacu), Bentsen-Rio Grande Valley State Park, Hidalgo Co. Texas (4 Feb 2010). A.jpg, Collared peccary (''

''), Hidalgo Co. Texas (4 Feb 2010). File:Mexican ground squirrel (Ictidomys mexicanus) Cameron Co. Texas (12 April 2016).jpg, Rio Grande ground squirrel ('' Ictidomys parvidens'') Cameron Co. Texas (12 April 2016). File:Btjackrabbit.jpg, Black-tailed jackrabbit (''

''), Texas (13 June 2006). File:Ocelot (Leopardus pardalis) Laguna Atascosa National Wildlife Refuge, Texas.jpg, Ocelot ('' Leopardus pardalis'') with tracking caller, Laguna Atascosa National Wildlife Refuge, Cameron Co. Texas. File:MexicanCoati2.jpg, White-nosed coati (''

''), Mexico (5 Sept 2009). File:Taxidea taxus (Point Reyes, 2007) cropped.jpg, American badger ('' Taxidea taxus''), Marin Co., California (25 Nov 2007). Birds: The southern part of the ecoregion is an Endemic Bird Area and is home to the red-crowned amazon (''

Amazona viridigenalis The red-crowned amazon (''Amazona viridigenalis''), also known as the red-crowned parrot, green-cheeked amazon or Mexican red-headed parrot, is an endangered amazon parrot native to northeastern Mexico and possibly southern Texas in the United St ...

''), tawny-collared nightjar ('' Caprimulgus salvini''), Tamaulipas crow (''

Corvus imparatus The Tamaulipas crow (''Corvus imparatus'') is a crow found in northeastern Mexico and southern Texas. Description It is a relatively small and sleek looking crow, in length. It has very glossy dark, bluish plumage, which appears soft and silky ...

''), long-billed thrasher ('' Toxostoma longirostre''), Altamira yellowthroat (''

Geothlypis flavovelata The Altamira yellowthroat (''Geothlypis flavovelata'') is a New World warbler. It is a resident breeding bird endemic to the Gulf slope of northeastern Mexico.Curson, Quinn and Beadle, ''New World Warblers'' It is closely related to common yell ...

''), and crimson-collared grosbeak ('' Rhodothraupis celaeno''). Other species occurring in this region include the white-tailed hawk ('' Buteo albicaudatus''), plain chachalaca ('' Ortalis vetula''), green parakeet (''

Psittacara holochlorus The green parakeet (''Psittacara holochlorus'') is a medium-sized parrot occurring in North and Central America, from the southernmost tip of Texas south to northern Nicaragua. Description The green parakeet is 32 cm in length, and is mos ...

''), buff-bellied hummingbird ('' Amazilia yucatanensis''), Couch's kingbird ('' Tyrannus couchii''), and Audubon's oriole ('' Icterus graduacauda'') as well as wide-ranging tropical species such as the green jay ('' Cyanocorax yncas''), least grebe ('' Tachybaptus dominicus''), Ferruginous pygmy owl ('' Glaucidium brasilianum''), ringed kingfisher ('' Megaceryle torquata''), and the great kiskadee (''

Pitangus sulphuratus The great kiskadee (''Pitangus sulphuratus''), called ''bem-te-vi'' in Brazil and ''benteveo'' in Argentina, is a passerine bird in the tyrant flycatcher family Tyrannidae. It is the only member of the genus ''Pitangus''. It breeds in open woodl ...

'').Howell, S. N. G. and S. Webb. (1995). A Guide to the Birds of Mexico and Northern Cantral America. Oxford University Press. Oxford. xvi, 851 pp. Terres, J. K. (1996). The Audubon Society Encyclopedia of North American Birds. Wings Books, a division of Random House Value Publishing, Inc.. New York. N. Y. 1109 pp. File:Ortalis vetula Linares.jpg, Plain chachalaca ('' Ortalis vetula''), Municipality of Montemorelos, Nuevo León (9 April 2009). File:Red-crowned Parrots (26460808665).jpg, Red-crowned Amazon (''

''), Cameron Co. Texas (15 Mar 2016). File:Ferruginous Pygny-Owl (26113203405).jpg, Ferruginous pygmy owl ('' Glaucidium brasilianum''), King Ranch, TX (15 Mar 2016). File:Buff-bellied Hummingbird (Amazilia yucatanensis) Sabal Palm C.jpg, Buff-bellied hummingbird ('' Amazilia yucatanensis''), Sabal Palm Sanctuary, Cameron Co. Texas (21 Sept. 2015). File:Great Kiskadee South Texas July 2011.jpg, Great kiskadee (''

''). Bee Co., Texas (3 July 2011). File:Long-billed Thrasher (34153001873).jpg, Long-billed thrasher ('' Toxostoma longirostre''), Texas, USA (20 Feb. 2017). File:Audubon's Oriole (12626811374).jpg, Audubon's oriole ('' Icterus graduacauda''), Starr Co. Texas (1 Feb 2014). Reptiles: The American alligator (''

Alligator mississippiensis The American alligator (''Alligator mississippiensis''), sometimes referred to colloquially as a gator or common alligator, is a large crocodilian reptile native to the Southeastern United States. It is one of the two extant species in the gen ...

'') and the red-eared slider (''

Trachemys scripta The pond slider (''Trachemys scripta'') is a species of common, medium-sized, semiaquatic turtle. Three subspecies are described, the most recognizable of which is the red-eared slider (''T. s. elegans''), which is popular in the pet trade and ha ...

'') occur in the north of this region and the Morelet's crocodile ('' Crocodylus moreletii'') and Mesoamerican slider (''

Trachemys venusta The Meso-American slider (''Trachemys venusta'') is a species of turtle belonging to the Family (biology), family Emydidae. The species is distributed from Mexico to Colombia. Geographic range The species ''Trachemys venusta'' is found from sou ...

'') in the south. Other turtles such as the Mexican box turtle ('' Terrapene mexicana''), Rio Grande cooter ('' Pseudemys gorzugi''), spiny softshell ('' Apalone spinifera''), and the yellow mud turtle ('' Kinosternon flavescens'') occur there. The geographic distribution of the Texas tortoise (''

Gopherus berlandieri The Texas tortoise (''Gopherus berlandieri''), is a species of tortoise in the family Testudinidae. The species ''G. berlandieri'' is one of six species of tortoises that are native to North America. Geographic range ''G. berlandieri'' is found ...

'') nearly matches that of the Tamaulipan mezquital ecoregion. The Laredo striped whiptail ('' Aspidoscelis laredoensis'') is a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

of all female lizards that reproduce by

parthenogenesis Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and developmen ...

that is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to this region. The reticulate collared lizard ('' Crotaphytus reticulatus'') is also endemic. Other representative lizards include the Texas banded gecko ('' Coleonyx brevis''), four-lined skink ('' Plestiodon tetragrammus''), common spotted whiptail ('' Aspidoscelis gularis''), keeled earless lizard (''

Holbrookia propinqua ''Holbrookia propinqua'' (keeled earless lizard) is a species of phrynosomatid lizard. Description The dorsal scales are small, pointed, and keeled, as the common name implies. The lateral scales are similar but smaller. The ventral scales ...

''), Texas horned lizard (''

Phrynosoma cornutum The Texas horned lizard (''Phrynosoma cornutum'') is one of about 14 North American species of spikey-bodied reptiles called horned lizards, all belonging the genus ''Phrynosoma''. It occurs in south-central regions of the US and northeastern Me ...

''), blue spiny lizard ('' Sceloporus cyanogenys''), and the northern rose-belly lizard ('' Sceloporus variabilis marmoratus''), regarded by some as a full species (''Sceloporus marmoratus''). Some representative snakes of the Tamaulipan mezquital include the Tamaulipan hook-nose snake ('' Ficimia streckeri''), Mexican milksnake ('' Lampropeltis annulata''), and Schott's whipsnake ('' Masticophis schotti''). More wide-ranging species include the Great Plains ratsnake ('' Pantherophis emoryi''), gopher snake ('' Pituophis catenifer''), long-nose snake ('' Rhinocheilus lecontei''), and eastern patch-nose snake ('' Salvadora grahamiae''). Some tropical species reaching the northern margin of their ranges including the regal black-striped snake ('' Coniophanes imperialis''), Central American indigo snake ('' Drymarchon melanurus''), speckled racer ('' Drymobius margaritiferus''), northern cat-eyed Snake ('' Leptodeira septentrionalis''). Venoumous snakes include the Texas coralsnake ('' Micrurus tener'') and western diamond-back rattlesnake (''

Crotalus atrox The western diamondback rattlesnake or Texas diamond-backWright AH, Wright AA. (1957). ''Handbook of Snakes''. Comstock Publishing Associates. (7th printing, 1985). . (''Crotalus atrox'') is a rattlesnake species and member of the viper family, ...

''), with the western massasauga rattlesnake ('' Sistrurus tergeminus'') occurring in the north and the Totonacan rattlesnake ('' Crotalus totonacus'') occurring in the south.Lemos Espinal, J. A., Editor. (2015). ''Amphibians and Reptiles of the US-Mexico Border States''. Texas A&M University Press. College Station, Texas. x, 614 pp. Werler, J. E. and J. R. Dixon. (2000). Texas Snakes, Identification, Distribution, and Natural History. University of Texas Press, Austin, Texas. xv, 437 pp. File:Sceloporus variabilis marmoratus, Northern Rose-bellied Lizard, Texas.jpg, Rose-bellied lizard ('' Sceloporus variabilis marmoratus''), Hidalgo County, Texas, USA (14 April 2016). File:Holbrookia propinqua, keeled earless lizard, Tamaulipas.jpg, Keeled earless lizard (''

''), municipality of Soto La Marina, Tamaulipas, Mexico (20 May 2002). File:Coleonyx brevis, Texas Banded Gecko, Webb Co. Texas.jpg, Texas banded gecko ('' Coleonyx brevis''), Webb County Texas, USA (10 June 2016). File:Gopherus berlandieri, Texas Tortoise, Tamaulipas.jpg, Texas Tortoise (''

''), northern Tamaulipas, Mexico (9 July 2007). File:Leptodeira septentrionalis, Northern Cat-eyed Snake, Tamaulipas.jpg, Northern cat-eyed snake ('' Leptodeira septentrionalis''), Municipality of Victoria, Tamaulipas, Mexico (7 Aug 2003). File:Mexican Milksnake (Lampropeltis annulata), Municipality of Victoria, Tamaulipas (30 Oct 2003).jpg, Mexican milksnake ('' Lampropeltis annulata''), Municipality of Victoria, Tamaulipas (30 Oct 2003). File:Crotalus atrox, Western Diamondback Rattlesnake, Tamaulipas.jpg, Western diamondback rattlesnake (''

''), Municipality of Padilla, Tamaulipas, Mexico (29 May 2004). Amphibians: In spite of the semi-arid environment, enough wetlands are present to support salamanders such as the black-spotted newt ('' Notophthalmus meridionalis'') and the lesser siren ('' Siren intermedia''). A second species of siren is known to occur in the lower Rio Grande, thought to be a distant and isolated population of the greater siren ('' Siren lacertina'') by some, or an undescribed species by others. The Rio Grande leopard frog (''

Lithobates berlandieri The Rio Grande leopard frog (''Lithobates berlandieri'' or ''Rana berlandieri'') is a species of aquatic frog native to the southern United States in Texas and New Mexico, and south through Mexico and Central America. It is also sometimes referre ...

'') and western narrow-mouthed toad (''

Gastrophryne olivacea ''Gastrophryne olivacea'', the Great Plains narrow-mouthed toad or western narrow-mouthed toad, is a species of microhylid frog found throughout much of the south-central United States from Nebraska south through Texas, and into northern Mexico. ...

'') occur in the region along with several toads (

Bufonidae {{Cat main, Toad This category contains both species commonly called toads, and the true toads from the family Bufonidae {{Cat main, Toad This category Category, plural categories, may refer to: Philosophy and general uses *Categorization, cat ...

) inhabiting the thorn scrub and grasslands including the green toad ('' Anaxyrus debilis''), Texas toad ('' Anaxyrus speciosus''), Gulf Coast toad ('' Incilius nebulifer''), and cane toad ('' Rhinella horribilis''). Many tropical species reach the northern limits of their distributions there such as the Mexican treefrog ('' Smilisca baudinii''), white-lipped frog (''

Leptodactylus fragilis ''Leptodactylus fragilis'', known under many common names such as the Mexican white-lipped frog, American white-lipped frog or simply white-lipped frog, is a species of leptodactylid frog. Its distribution ranges from the Lower Rio Grande Val ...

''), sheep frog (''

Hypopachus variolosus ''Hypopachus'' is a genus of microhylid frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The ...

''), and the unusual burrowing toad (''

Rhinophrynus dorsalis This frog belongs to the Family ''Rhinophrynidae'' and Genus Rhinophrynus. Rhinophrynus dorsalis is the only living representation of the family Rhinophrynidae. This family is also known as the burrowing toads, and is evidently a small and specia ...

''), so unique it is classified in a family (

Rhinophrynidae The Rhinophrynidae are a family of frogs containing one extant genus, the monotypic '' Rhinophrynus'', and a number of fossil genera. The family is sometimes known as the Mexican burrowing toads or simply burrowing toads. ''Rhinophrynus'' occur ...

) by itself. File:Smilisca baudinii WLF-17-14A, Municipio Abasolo; 18 May 2002.jpg, Mexican Treefrog ('' Smilisca baudinii''), Municipality of Abasolo, Tamaulipas, Mexico (18 May 2002). File:Leptodactylus fragilis WLF-152-1A, Municipio Victoria; 12 Aug 2003.jpg, White-lipped Frog (''

'') Municipality of Victoria, Tamaulipas, Mexico (12 August 2003). File:Scaphiopus couchii, Couch’s Spadefoot, Cameron County, Texas.jpg, Couch's Spadefoot ('' Scaphiopus couchii''), Cameron County, Texas, USA (11 April 2016). File:Black-spotted Newt (Notophthalmus meridionalis), Santa Ana NWR, Hidalgo Co, TX, USA, (26.0821°N, 98.1354°W), 14 April 2016.jpg, Black-spotted Newt ('' Notophthalmus meridionalis''), Santa Ana NWR, Hidalgo Co, Texas (14 April 2016). File:Rhinella horribilis, Cane Toad, Tamaulipas.jpg, Cane Toad ('' Rhinella horribilis''), Municipality of Soto La Marina, Tamaulipas, Mexico (17 May 2002). File:Hypopachus variolosus WLF-148-10A, Municipio Victoria; 12 Aug 2003.jpg, Sheep Frog (''

''), Municipality of Victoria, Tamaulipas, Mex (12 August 2003). File:Rhinophrynus dorsalis, Burrowing Toad, Tamaulipas.jpg, Burrowing Toad (''

''), Municipality of Reynosa, Tamaulipas, Mexico (8 October 2007). Fishes: Two species, the San Ignacio pupfish ('' Cyprinodon bobmilleri'') from the upper Rio San Fernando basin near Linares and the swordtail platyfish ('' Xiphophourus xiphidium'') occurring in the upper parts of the Rio Soto La Maria, in Tamaulipas are

to this region. The Amazon molly ('' Poecilia formosa''), is a unisexual (all female) species that reproduces through

gynogenesis Gynogenesis, a form of parthenogenesis, is a system of asexual reproduction that requires the presence of sperm without the actual contribution of its DNA for completion. The paternal DNA dissolves or is destroyed before it can fuse with the egg. Th ...

, a form of a form of

. Other fishes found in the area are alligator gar ('' Atractosteus spatula''), longnose gar ('' Lepisosteus osseus''), Rio Grande cichlid (''

Herichthys cyanoguttatus The Texas cichlid (''Herichthys cyanoguttatus'', formerly ''Cichlasoma cyanoguttatum'') is a freshwater fish of the cichlid family. This is the only cichlid species that is native to the United States. The fish, also known as Rio Grande cichl ...

''), sailfin molly (''

Poecilia latipinna ''Poecilia'' is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. These livebearers are native to fresh, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to liv ...

''), Rio Grande silvery minnow (''

Hybognathus amarus The Rio Grande silvery minnow or Rio Grande minnow (''Hybognathus amarus'') is a small herbivorous North American fish. It is one of the seven North American members of the genus '' Hybognathus'', in the cyprinid family. The Rio Grande silvery mi ...

''), San Juan minnow ('' Dionda couchi''), Tamaulipas shiner ('' Notropis braytoni''), Rio Grande shinner ('' Notropis jemezanus''), Gulf killifish ('' Fundulus grandis''), and Rio Grande darter ('' Etheostoma grahami''). Two endemic species from this region, the phantom shinner ('' Notropis orca'') and the Salado shinner ('' Notropis saladonis''), are believed to be extinct.García de León, Francisco J., Delladira Gutiérrez Tirado, Dean A. Hendrickson, and Héctor Espinosa Pérez (2005). ''Fishes of the Continental Waters of Tamaulipas: Diversity and Conservation Status''. ''In'' Jean-Luc E. Cartron, Gerardo Ceballos, and Richard S. Felger (eds.). ''Biodiversity, Ecosystems, and Conservation in Northern Mexico''. Oxford University Press, Inc. New York, N. Y. xvi, 496 pp. Miller, R. R., W. L. Minckley, and S. M. Norris. (2005). ''Freshwater Fishes of Mexico''. University of Chicago Press. Chicago, Illinois. xxv, 490 pp. Thomas, Chad, Timothy H. Bonner, & Bobby G. Whiteside. (2007). ''Freshwater Fishes of Texas: A Field Guide''. Texas A&M University Press. College Station, Texas. xiv, 202 pp. File:Molly.jpg, Sailfin molly (''

'') File:Etheostoma grahami.jpg, Rio Grande darter ('' Etheostoma grahami''), Val Verde Co., Texas (22 June 2006). File:Gulf killifish (Fundulus grandis), male, Dixie Co, Florida (27 Dec 2013).jpg, Gulf killifish ('' Fundulus grandis''), male, Dixie Co., Florida. File:Rio Grande silvery minnow 2.jpg, Rio Grande silvery minnow (''

'') File:Herichthys cyanoguttatus (Rio Grande Cichlid) II.jpg, Rio Grande cichlid (''

''), Texas File:Ybgar 2b (8379903165).jpg, Longnose gar ('' Lepisosteus osseus'') File:Alligator gar (Atractosteus spatula) I.jpg, Alligator gar ('' Atractosteus spatula'')

Protected areas

Nature preserves are numerous in the region, however many are relatively small tracts of land concentrated on the north side of the

Lower Rio Grande Valley The Lower Rio Grande Valley ( es, Valle del Río Grande), commonly known as the Rio Grande Valley or locally as the Valley or RGV, is a region spanning the border of Texas and Mexico located in a floodplain of the Rio Grande near its mouth. The ...

. The state of Texas administers the following lands in the Lower Rio Grande Valley: Lake Casa Blanca International State Park (525-acres); Falcon State Park (576 acres); Bentsen-Rio Grande Valley State Park (764 acres); Estero Llano Grande State Park (230 acres);

Resaca de la Palma State Park Resaca de la Palma State Park is one of three state parks belonging to the World Birding Center and managed by the Texas Parks and Wildlife Department. At 1,200 acres, Resaca de la Palma State Park is the largest of the World Birding Center sites ...

(1,200 acres); and the Las Palomas Wildlife Management Area comprised 18 units with tracts ranging from two to 604 acres (3,311 acres total). The U. S. Federal Government also administers lands in the

including the

(2,088 acres) and western and higher elevation areas of the

Laguna Atascosa National Wildlife Refuge Laguna Atascosa National Wildlife Refuge is the largest protected area of natural habitat left in the Lower Rio Grande Valley. The refuge is located almost entirely in Cameron County, Texas (near Harlingen), although a very small part of its n ...

on the Gulf Coast (>97, 000 acres). The multi-unit Lower Rio Grande Valley National Wildlife Refuge has nearly 40,000 acres open to the public .g. the Boca Chica tract (10,680-acres), East Lake unit (1,700 acres), La Puerta unit (4,000 acres), Teniente Lake unit (5,600 acres), Yturria Brush unit (1,800 acres)and an additional 6,000 acres open to hunting s of 2020 Also of note is the Sabal Palm Sanctuary (557-acres), cooperatively manage by the Gorgas Science Foundation and the National Audubon Society, preserving some of the finest old growth

and sabal palm groves (''

'') remaining. Beyond the Lower Rio Grande Valley of Texas protected lands include the Chaparral Wildlife Management Area (15,200 acres), Lake Corpus Christi State Park (356 acres), and Choke Canyon State Park: including the Calliham unit (1,100 acres), the South Shore unit (385-acres), and the adjoining James E. Daughtrey Wildlife Management Area (34,000 acres). In

, Mexico protected areas include western portions of the Laguna Madre y Delta del Rio Bravo and Parras de la Fuente, Reserva de la Paloma de Ala Blanca (ca. 23.8888°N, 98.5000°W), and in Coahuila, Mexico the Parque Nacional Los Novillos. Many of the protected lands in Mexico are actually "paper parks" owned and administer by local

ejido An ''ejido'' (, from Latin ''exitum'') is an area of communal land used for agriculture in which community members have usufruct rights rather than ownership rights to land, which in Mexico is held by the Mexican state. People awarded ejidos in ...

s and municipalities, with few resources devoted to their management, no accommodations, no facilities or trails for visitors, and little management or enforcement of wildlife regulations. Nonetheless, such parks do limit land usage and development, and thus provide a significant degree of protection for habitat and the flora and fauna within.Gobierno del México
76 aniversario del Parque Nacional Los Novillos
/ref>

References

{{reflist Deserts and xeric shrublands in the United States Nearctic ecoregions Ecoregions of the United States Deserts and xeric shrublands Ecoregions of Mexico Deserts of Mexico Deserts of Texas Gulf Coast of Mexico Gulf Coast of the United States Geography of Texas Sierra Madre Oriental Natural history of Nuevo León Natural history of Tamaulipas