''Hoffmannseggia tenella'' is a rare species of flowering plant in the legume family known by the common name slender rushpea. It 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 elsew ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

, 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 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 and inv ...

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.USFWS
Slender Rushpea Five-year Review.
July 2008. 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 Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...

, or

salmon Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the ...

.''Hoffmannseggia tenella''.

The Nature Conservancy The Nature Conservancy (TNC) is a global environmental organization headquartered in Arlington, Virginia. it works via affiliates or branches in 79 countries and territories, as well as across every state in the US. Founded in 1951, The Natu ...

The blooming season is in March through June, and more blooming may occur later if there is adequate

rainfall Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...

.''Hoffmannseggia tenella''.
Texas Parks & Wildlife. The fruit is a flat, straight

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...

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 The shortgrass prairie is an ecosystem located in the Great Plains of North America. The two most dominant grasses in the shortgrass prairie are blue grama (''Bouteloua gracilis'') and buffalograss (''Bouteloua dactyloides''), the two less domina ...

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 ''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 ...

(''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'' 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 ...

(''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 Agriculture or farming is the practice of cultivating Plant, plants and livestock. Agriculture was the key development in the rise of Sedentism, sedentary human civilization, whereby farming of Domestication, domesticated species created food ...

use as cropland and

pasture Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") 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 ...

s. The land has also been

invaded An invasion is a military offensive in which large numbers of combatants of one geopolitical entity aggressively enter territory owned by another such entity, generally with the objective of either: conquering; liberating or re-establishing con ...

by non-native plant species that compete with the rare plant. The worst offender is Kleberg bluestem (''Dichanthium annulatum''), a large

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 natural grassland and species cultivated in lawns an ...

. It grows very quickly and tall, shading out the slender rushpea. The dense habit of the grass may hold in heat and

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

, which foster the growth of

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

on the

seedling A seedling is a young 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 (embryonic root), the hypocotyl (embry ...

s of the rushpea. It drains nutrients and water from the soil, and it may produce

allelopathic Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the germination, growth, survival, and reproduction of other organisms. These biochemicals are known as allelochemicals and can have ben ...

substances that discourage growth of the rushpea.

References

External links

USDA Plants Profile for ''Hoffmannseggia tenella''
Caesalpinieae Endemic flora of Texas Critically endangered flora of the United States {{Caesalpinioideae-stub