''Aeschynomene virginica'' is a rare species of flowering plant in the legume family known by the common names Virginia jointvetch and sensitive jointvetch. It is native to a small section of the East Coast of the United States, where it has a fluctuating annual global population scattered in about 20 mostly small occurrences. Counts and estimates revealed two populations in

New Jersey New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...

including several thousand individuals, one population of a few hundred plants in

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

, several variable and unstable populations in ditches in

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

, and several populations including about 5000 individuals in

Virginia Virginia, officially the Commonwealth of Virginia, is a U.S. state, state in the Southeastern United States, Southeastern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States between the East Coast of the United States ...

.Center for Plant Conservation
Habitat alteration has reduced the number of sites where the plant can grow. The plant became a federally listed threatened species of the United States in 1992. Some confusion has occurred in the literature, specifically that this species is named as a

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is harmful to agricultural or horticultural crops, natural habitats or ecosystems, or humans or lives ...

soybean The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean. Soy is a staple crop, the world's most grown legume, and an important animal feed. Soy is a key source o ...

and rice fields.Smith, R. J. (1986). Biological control of Northern Jointvetch (''Aeschynomene virginica'') in rice (''Oryza sativa'') and soybeans (''Glycine max''): A researcher's view. ''Weed Science'' 34, supp 1: Microbiological Control of Weeds Symposium. 17-23. The weedy species in question is actually '' Aeschynomene indica'', not the rare and threatened ''A. virginica''.Carulli, J. P. and D. E. Fairbrothers. (1988). Allozyme variation in three Eastern United States species of ''Aeschynomene'' (Fabaceae), including the rare ''A. virginica''. ''Systematic Botany'' 13:4 559-566. Aeschnyomene virginica drawing

''A. virginica'' is an annual herb which grows erect and can reach two meters in height. The alternately arranged leaves are each made up of many pairs of hairy, glandular leaflets. The leaves are touch-sensitive, folding when touched. Blooming takes place in summer and early fall. The pea-like flower is about a centimeter long and yellow in color with stark red veining. The flowers are

pollinated Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or butterflies; bird ...

by insects such as the least skipper (''Ancylozypha numitor'') and leaf-cutter bees (family Megachilidae). The fruit is a

legume Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consum ...

pod up to 7 centimeters long which is narrowed between the seeds and easily segments. The segments float and the seeds may be dispersed on the water if they don't fall out immediately. Bits of the pods may get caught up in floating vegetation debris and can be deposited with it in new territory. This plant occurs in

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

tidal marsh A tidal marsh (also known as a type of "tidal wetland") is a marsh found along rivers, coasts and estuaries which floods and drains by the tidal movement of the adjacent estuary, sea or ocean.

es that experience tidal action but low

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

. It grows in bare, disturbed areas that are mostly cleared of other vegetation, such as newly deposited shorelines or recently disturbed terrain dug out by

muskrat The muskrat or common muskrat (''Ondatra zibethicus'') is a medium-sized semiaquatic rodent native to North America and an introduced species in parts of Europe, Asia, and South America. The muskrat is found in wetlands over various climates ...

s. It

germinates Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an flowering plant, angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the sp ...

in wet soils but not in submerged areas, and it is not successful in areas with thick vegetation.Griffith, A. B. and I. N. Forseth. (2003). Establishment and reproduction of ''Aeschynomene virginica'' (L.) (Fabaceae) a rare, annual, wetland species in relation to vegetation removal and water level. ''Plant Ecology'' 167:1 117. Despite its ability to take hold in tidally disturbed habitat it cannot withstand severe disturbance, such as patterns of increased

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

ation, and human activity such as development,

pollution Pollution is the introduction of contaminants into the natural environment that cause harm. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the component ...

, or

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

from boat wakes.

References

External links

USDA Plants Profile
{{Taxonbar, from=Q4688543 virginica Flora of the Eastern United States Plants described in 1753 Taxa named by Carl Linnaeus