''Ayenia limitaris'' is a rare North American species of flowering plant in the mallow family known by the common names Rio Grande ayenia, Texas ayenia, and Tamaulipan kidneypetal. It is native to an area straddling the

Rio Grande The Rio Grande ( or ) in the United States or the Río Bravo (del Norte) in Mexico (), also known as Tó Ba'áadi in Navajo language, Navajo, is one of the principal rivers (along with the Colorado River) in the Southwestern United States a ...

in Mexico and the United States. Today it is known from far southern

Texas Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...

and far northern sections of the Mexican states of

Coahuila Coahuila, formally Coahuila de Zaragoza, officially the Free and Sovereign State of Coahuila de Zaragoza, is one of the 31 states of Mexico. The largest city and State Capital is the city of Saltillo; the second largest is Torreón and the thi ...

and

Tamaulipas Tamaulipas, officially the Free and Sovereign State of Tamaulipas, is a state in Mexico; one of the 31 states which, along with Mexico City, comprise the 32 federal entities of Mexico. It is divided into 43 municipalities. It is located in nor ...

. It has become rare because most of its habitat has been degraded or destroyed.Center for Plant Conservation
There are perhaps four populations remaining in Texas and two in Mexico, for a total of 1000 individual plants at most.The Nature Conservancy
/ref> It is a federally listed

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

of the United States. This is a

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

growing up to 1.5 meters (5 feet) tall. The alternately arranged leaves have hairy heart-shaped blades with toothed edges. The small flowers have pinkish, greenish, or whitish petals. The fruit is a prickly capsule divided into five cells. The plant's native habitat was made up of

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

riparian A riparian zone or riparian area is the interface between land and a river or stream. In some regions, the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor, and riparian strip are used to characterize a ripar ...

woodland covered in dense thickets in the

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

s of the Rio Grande

delta Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...

. It is probably adapted to periodic

flood A flood is an overflow of water (list of non-water floods, or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are of significant con ...

ing in the area, an event that is largely contained and prevented today.Texas Parks and Wildlife
/ref> Only about 5% of the natural habitat, the Texas ebony-anacua (''

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 language, Span ...

''/'' Ehretia anacua'') plant community, remains in this area.USFWS
Determination of endangered status for the plants ''Ayenia limitaris'' and ''Ambrosia cheiranthifolia''.
''Federal Register'' August 24, 1994. the rest has been

fence A fence is a structure that encloses an area, typically outdoors, and is usually constructed from posts that are connected by boards, wire, rails or net (textile), netting. A fence differs from a wall in not having a solid foundation along its ...

d and fragmented by

road A road is a thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. Th ...

canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface ...

s, and

ditch A ditch is a small to moderate trench created to channel water. A ditch can be used for drainage, to drain water from low-lying areas, alongside roadways or fields, or to channel water from a more distant source for plant irrigation. Ditches ...

es, plowed for

agricultural Agriculture encompasses crop and livestock production, aquaculture, and forestry for food and non-food products. Agriculture was a key factor in the rise of sedentary human civilization, whereby farming of domesticated species created f ...

use, and compacted by herds of

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

. Introduced plant species such as Guinea grass (''Megathyrsus maximus'') have taken hold. '' Metcalfa pruinosa'', a

true bug Hemiptera (; ) is an order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to a ...

, feeds on the plant.USFWS
Texas ''Ayenia'' 5-year review: Summary and Evaluation.
/ref>

References

External links

United States Department of Agriculture Plants ProfileTexas Parks and Wildlife Department U.S. Fish and Wildlife Service
{{Taxonbar, from=Q4831152 limitaris Plants described in 1960 Flora of Texas Flora of Coahuila Flora of Tamaulipas Flora of the Rio Grande valleys Endangered flora of the United States