Hoffmannseggia tenella
Encyclopedia
Hoffmannseggia tenella is a rare species of flowering plant in the legume family
known by the common name slender rushpea. It is endemic to Texas
, where it is known from only two counties. It persists in small remnants of its gulf coastal prairie
habitat. It is a federally listed endangered species
of the United States.
This is a small perennial herb growing up to 15 centimeters tall from a woody taproot
. It may grow in colonies. The plant has leaves up to 6 centimeters long which are made up of 5 to 7 pairs of leaflets. The flowers have petals about half a centimeter long in shades of yellowish pink, orange, coral
, or salmon
. The blooming season is in March through June, and more blooming may occur later if there is adequate rainfall. The fruit is a flat, straight legume pod just over a centimeter long.
This plant is known only from Nueces and Kleberg Counties in Texas. The natural habitat of this species is a type of coastal shortgrass prairie
dominated by native grasses such as buffalograss (Buchloe dactyloides), Texas wintergrass (Stipa leucotrica), and Texas grama (Bouteloua rigidiseta). Other plants in the habitat include huisache (Acacia farnesiana), huisachillo
(Acacia schaffneri), spiny hackberry
(Celtis laevigata), brasil (Condalia hookeri), retama
(Parkinsonia aculeata), lotebush
(Ziziphus obtusifolia), tasajillo (Opuntia leptocaulis), and Engelmann's prickly pear
(Opuntia engelmannii). The rushpea sometimes grows alongside the South Texas ambrosia
(Ambrosia cheiranthifolia), another endangered species.
It has a patchy distribution in remaining strips of appropriate habitat, occurring in just 15% of its former range. Most of its habitat has been converted to agricultural
use as cropland and pasture
s. The land has also been invaded
by non-native plant species
that compete
with the rare plant. The worst offender is Kleberg bluestem (Dichanthium annulatum), a large grass
. It grows very quickly and tall, shading out the slender rushpea. The dense habit of the grass may hold in heat and humidity
, which foster the growth of fungi on the seedling
s of the rushpea. It drains nutrients and water from the soil, and it may produce allelopathic
substances that discourage growth of the rushpea.
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
known by the common name slender rushpea. It is endemic 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...
, where it is known from only two counties. It persists in small remnants of its gulf coastal prairie
Western Gulf coastal grasslands
The Western Gulf coastal grasslands are a subtropical grassland ecoregion of the southern United States and northeastern Mexico. It is known in Texas as "Coastal Prairie" and as the Tamaulipan pastizal in Mexico.-Setting:...
habitat. It is a federally listed 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 small perennial herb growing up to 15 centimeters tall from a woody taproot
Taproot
A taproot is an enlarged, somewhat straight to tapering plant root that grows vertically downward. It forms a center from which other roots sprout laterally.Plants with taproots are difficult to transplant...
. It may grow in colonies. The plant has leaves up to 6 centimeters long which are made up of 5 to 7 pairs of leaflets. The flowers have petals about half a centimeter long in shades of yellowish pink, orange, coral
Coral (color)
The various tones of the color coral are representations of the wide range of colors of the class of cnidarians, also called corals. The complementary color of coral is teal.-Coral:The web color coral is a pinkish-orange color...
, or salmon
Salmon (color)
Salmon a range of pale pinkish-orange to light pink colors, named after the color of salmon flesh.The web color salmon is displayed at right.The first recorded use of salmon as a color name in English was in 1776...
. The blooming season is in March through June, and more blooming may occur later if there is adequate rainfall. The fruit is a flat, straight legume pod just over a centimeter long.
This plant is known only from Nueces and Kleberg Counties in Texas. The natural habitat of this species is a type of coastal shortgrass prairie
Shortgrass prairie
The shortgrass prairie ecosystem of the North American Great Plains is a prairie that includes lands from the eastern foothills of the Rocky Mountains east to Nebraska and Saskatchewan, including rangelands in Alberta, Wyoming, Montana, North, South Dakota, and Kansas, and extending to the south...
dominated by native grasses such as buffalograss (Buchloe dactyloides), Texas wintergrass (Stipa leucotrica), and Texas grama (Bouteloua rigidiseta). Other plants in the habitat include huisache (Acacia farnesiana), huisachillo
Acacia schaffneri
Acacia schaffneri is a tree native to Mexico and the United States .-Uses:Acacia schaffneri wood is used for fuel and fences. The wood makes very good firewood. It is used for cooking....
(Acacia schaffneri), spiny 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....
(Celtis laevigata), brasil (Condalia hookeri), 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, and jelly bean tree.-Etymology:...
(Parkinsonia aculeata), lotebush
Ziziphus obtusifolia
Ziziphus obtusifolia is a species of flowering plant in the buckthorn family known by several common names, incluging lotebush, graythorn, gumdrop tree, and Texas buckthorn. It is native to the southwestern United States and much of Mexico, where it grows in shrubby and scrubby desert habitat,...
(Ziziphus obtusifolia), tasajillo (Opuntia leptocaulis), and Engelmann's prickly pear
Opuntia engelmannii
Opuntia engelmannii is a prickly pear common across the Southwestern United States and northern Mexico. It goes by a variety of common names, including "cow's tongue cactus", "cow tongue prickly pear", "desert prickly pear", "discus prickly pear", "Engelmann's prickly pear", and "Texas prickly...
(Opuntia engelmannii). The rushpea sometimes grows alongside the South Texas ambrosia
Ambrosia cheiranthifolia
Ambrosia cheiranthifolia is a rare species of flowering plant known by the common names South Texas ambrosia and Rio Grande ragweed. It is native to the coast of South Texas and the Mexican state of Tamaulipas, where it occurs in coastal prairie, grassland, and mesquite shrubland habitat...
(Ambrosia cheiranthifolia), another endangered species.
It has a patchy distribution in remaining strips of appropriate habitat, occurring in just 15% of its former range. Most of its habitat has been converted to 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 as cropland and 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. The land has also been invaded
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
by non-native 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...
that compete
Competition (biology)
Competition is an interaction between organisms or species, in which the fitness of one is lowered by the presence of another. Limited supply of at least one resource used by both is required. Competition both within and between species is an important topic in ecology, especially community ecology...
with the rare plant. The worst offender is Kleberg bluestem (Dichanthium annulatum), a large grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...
. It grows very quickly and tall, shading out the slender rushpea. The dense habit of the grass may hold in heat and humidity
Humidity
Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...
, which foster the growth of fungi on the seedling
Seedling
thumb|Monocot and dicot seedlingsA seedling is a young plant sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle , the hypocotyl , and the cotyledons...
s of the rushpea. It drains nutrients and water from the soil, and it may produce allelopathic
Allelopathy
Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have beneficial or detrimental effects on the target organisms...
substances that discourage growth of the rushpea.