Lesquerella thamnophila (syn.

Synonym (taxonomy)

In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

 Physaria thamnophila) is a rare species of flowering plant in the mustard family

Brassicaceae

Brassicaceae, a medium sized and economically important family of flowering plants , are informally known as the mustards, mustard flowers, the crucifers or the cabbage family....

 known by the common name Zapata bladderpod. It is native to Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 in the United States, where it is known from Zapata and Starr Counties

Starr County, Texas

Starr County is a county located in the U.S. state of Texas. In 2010, its population was 60,968. Its county seat is Rio Grande City. The county is named for James Harper Starr, who served as Secretary of the Treasury of the Republic of Texas. It is part of the Rio Grande City-Roma, TX,...

. The plant is threatened by the loss and degradation of its habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

. It is federally listed as an endangered species

Endangered species

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

.

This is a perennial herb producing one or more spreading stems from a woody base. The stems grow to 80 centimeters in maximum length. The herbage is silvery in color due to a coat of branching hairs. The leaves are oval to lance-shaped and smooth to faintly toothed on the edges, the lowest leaves reaching 12 centimeters long. The inflorescence

Inflorescence

An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 is a raceme

Raceme

A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...

 of yellow flowers. Blooming can occur through September whenever there is enough moisture. The population size can also increase rapidly after a significant amount of rainfall.

This plant grows in desert shrublands above the Rio Grande

Rio Grande

The Rio Grande is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes...

 floodplain

Floodplain

A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...

 in southern Texas. The substrate is calcareous

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 clay and sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 in geologic formation

Geologic formation

A formation or geological formation is the fundamental unit of lithostratigraphy. A formation consists of a certain number of rock strata that have a comparable lithology, facies or other similar properties...

s that contain an abundance of fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s. The terrain is sparsely covered by thorny shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

s and cacti

Cactus

A cactus is a member of the plant family Cactaceae. Their distinctive appearance is a result of adaptations to conserve water in dry and/or hot environments. In most species, the stem has evolved to become photosynthetic and succulent, while the leaves have evolved into spines...

, with the plant community dominated by Leucophyllum frutescens

Leucophyllum frutescens

Leucophyllum frutescens is an evergreen shrub in the figwort family, Scrophulariaceae, native to the state of Texas in the southwestern United States and the states of Coahuila, Nuevo León, and Tamaulipas in northern Mexico. Although commonly known as Texas Sage, it is not a true sage and is...

and Acacia berlandieri

Acacia berlandieri

Acacia berlandieri is a shrub native to the Southwestern United States and northeast Mexico that belongs to the subfamily Mimosoideae of Fabaceae . It grows tall, with blossoms that are spherical and white, occurring from February through April...

. Other plants in the habitat include Acacia rigidula

Acacia rigidula

Acacia rigidula, commonly known as Blackbrush Acacia or Chaparro Prieto, is a species of shrub or small tree in the legume family, Fabaceae. Its native range stretches from Texas in the United States south to central Mexico. This perennial is closely related to A. berlandieri and is not listed as...

(blackbrush acacia), Prosopis

Prosopis

Prosopis is a genus of flowering plants in the pea 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 arid soil and are resistant to drought, on occasion...

spp. (mesquite), Celtis pallida (granjeno), Yucca treculeana (Spanish dagger), Zizyphus obtusifolia (lotebush), and Guaiacum angustifolium

Guaiacum angustifolium

Guaiacum angustifolium is a species of flowering plant in the caltrop family, Zygophyllaceae. Common names include Texas Guaiacum, Texas Lignum-vitae, Soapbush and Guayacán. It is native to southern and western Texas in the United States and northern Mexico...

(guayacan). Some shrubs may serve as nurse plants

Nurse tree

A nurse tree is a larger, faster-growing tree that shelters a smaller, slower-growing tree or plant. The nurse tree can provide shade, shelter from wind, or protection from animals who would feed on the smaller plant....

 to the bladderpod, which grows in their shade and may benefit from their protection from soil erosion

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 and herbivory by animals.

This plant was thought to be limited to Zapata and Starr Counties in Texas, but there has been a documented population south of the border in Tamaulipas

Tamaulipas

Tamaulipas officially Estado Libre y Soberano de Tamaulipas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 43 municipalities and its capital city is Ciudad Victoria. The capital city was named after Guadalupe Victoria, the...

 and the plant may occur in Webb County, Texas

Webb County, Texas

Webb County is a county located in the U.S. state of Texas. The official 2010 population for the county is 250,304. In 2000, its population was 193,117, and in 2006 its population had been estimated to have reached to 231,470. Its county seat is Laredo...

. There are approximately eleven populations known, but only about seven of these still exist. During dry spells the populations can shrink to low numbers, but flourish again when rain occurs.

The main threat to the species is habitat destruction and modification. Non-native grass

Introduced species

An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

 species have been introduced to the region to make pasture

Pasture

Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...

s for grazing

Grazing

Grazing generally describes a type of feeding, in which a herbivore feeds on plants , and also on other multicellular autotrophs...

. Some areas have then become overgrazed

Overgrazing

Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, or by overpopulations of native or non-native wild animals.Overgrazing reduces the...

. The landscape has been cleared and developed and associated infrastructure

Infrastructure

Infrastructure is basic physical and organizational structures needed for the operation of a society or enterprise, or the services and facilities necessary for an economy to function...

 has been installed, including highway

Highway

A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...

s and transmission lines. There is active petroleum exploration occurring in the area.