Ayenia limitaris
Encyclopedia
Ayenia limitaris is a rare 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
. Today it is known from far southern
Texas
and far northern sections of the Mexican states of Coahuila
and Tamaulipas
. It has become rare because most of its habitat has been degraded or destroyed. There are perhaps four occurrences remaining in Texas and two in Mexico, for a total of 1000 individual plants at most. It is a federally listed
endangered species
of the United States.
This is a shrub
growing up to 1.5 meters 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
riparian
woodland covered in dense thickets in the floodplain
s of the Rio Grande delta
. It is probably adapted to periodic flood
ing in the area, an event that is largely contained and prevented today. Only about 5% of the natural habitat, the Texas ebony-anacua (Ebenopsis ebano
/Ehretia anacua
) plant community, remains in this area. the rest has been fence
d and fragmented by road
s, canal
s, and ditch
es, plowed for agricultural
use, and compacted by herds of cattle
. Introduced plant species
such as Guinea grass
(Megathyrsus maximus) have taken hold.
Ormenis pruinosa, a bug
, feeds on the plant.
Malvaceae
Malvaceae, or the mallow family, is a family of flowering plants containing over 200 genera with close to 2,300 species. Judd & al. Well known members of this family include okra, jute and cacao...
known by the common names Rio Grande ayenia, Texas ayenia, and Tamaulipan kidneypetal. It is native to an area straddling 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...
. Today it is known from far southern
Rio Grande Valley
The Rio Grande Valley or the Lower Rio Grande Valley, informally called The Valley, is an area located in the southernmost tip of South Texas...
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...
and far northern sections of the Mexican states of Coahuila
Coahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...
and 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...
. It has become rare because most of its habitat has been degraded or destroyed. There are perhaps four occurrences remaining in Texas and two in Mexico, for a total of 1000 individual plants at most. It is a federally listed
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
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...
of the United States.
This is a 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...
growing up to 1.5 meters 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
Subtropics
The subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...
riparian
Riparian zone
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 fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...
woodland covered in dense thickets in the 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...
s of the Rio Grande delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...
. It is probably adapted to periodic flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
ing in the area, an event that is largely contained and prevented today. Only about 5% of the natural habitat, the Texas ebony-anacua (Ebenopsis ebano
Ebenopsis ebano
Ebenopsis ebano is a species of flowering plant in the pea 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 Ébano ....
/Ehretia anacua
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, as is that of the related Cordia boissieri, the Anacahuita...
) plant community, remains in this area. the rest has been fence
Fence
A fence is a freestanding structure designed to restrict or prevent movement across a boundary. It is generally distinguished from a wall by the lightness of its construction: a wall is usually restricted to such barriers made from solid brick or concrete, blocking vision as well as passage .Fences...
d and fragmented by road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
s, canal
Canal
Canals are man-made channels for water. There are two types of canal:#Waterways: navigable transportation canals used for carrying ships and boats shipping goods and conveying people, further subdivided into two kinds:...
s, and ditch
Ditch
A ditch is usually defined as a small to moderate depression created to channel water.In Anglo-Saxon, the word dïc already existed and was pronounced 'deek' in northern England and 'deetch' in the south. The origins of the word lie in digging a trench and forming the upcast soil into a bank...
es, plowed for agricultural
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
use, and compacted by herds of cattle
Cattle
Cattle are the most common type of large domesticated ungulates. They are a prominent modern member of the subfamily Bovinae, are the most widespread species of the genus Bos, and are most commonly classified collectively as Bos primigenius...
. Introduced plant species
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...
such as Guinea grass
Megathyrsus maximus
Megathyrsus maximus, known as Guinea Grass or Green Panic Grass in English, is a large perennial bunch grass that is native to Africa Palestine, and Yemen. It has been introduced in the tropics around the world. Due to its wide distribution, it has common names in a large number of languages and...
(Megathyrsus maximus) have taken hold.
Ormenis pruinosa, a bug
Hemiptera
Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...
, feeds on the plant.