Sphaerophysa salsula
Encyclopedia
Sphaerophysa salsula is a species of flowering plant in the legume family
known by the common names alkali swainsonpea, Austrian peaweed, and red bladder-vetch. It is native to Asia but it is known in many other parts of the world as an introduced species
and often a noxious weed. It grows in cultivated land and disturbed habitat, easily tolerating alkaline substrates. It is commonly seen in areas where alfalfa
is grown, because the seeds of the two species look similar and the weed seed is easily imported with the crop seed.
This is a long-lived perennial herb growing up to 1.5 meters tall. It reproduces via seed as well as by sprouting vigorously from its creeping root system. The stems are coated in short white hairs. The leaves are made up of many oval leaflets each up to two centimeters long. The inflorescence
is a raceme
of several pea-like flowers each just over a centimeter wide. They may be brick-red to deep pink to brownish or red-orange in color. The fruit is a legume pod up to 3.5 centimeters long. It is inflated and bladderlike, hairless, translucent, shiny, and papery when dry. It is mottled greenish or reddish. It contains several seeds each about two millimeters long.
Like other legumes, this plant contains endophyte
s. These include the bacterium Paracoccus sphaerophysae, which was recently isolated from the roots of this species, and named for it. Other rhizobia
in this species include Shinella kummerowiae and species of the genera Rhizobium
, Agrobacterium
, and Mesorhizobium
.
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 names alkali swainsonpea, Austrian peaweed, and red bladder-vetch. It is native to Asia but it is known in many other parts of the world as an introduced 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...
and often a noxious weed. It grows in cultivated land and disturbed habitat, easily tolerating alkaline substrates. It is commonly seen in areas where alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
is grown, because the seeds of the two species look similar and the weed seed is easily imported with the crop seed.
This is a long-lived perennial herb growing up to 1.5 meters tall. It reproduces via seed as well as by sprouting vigorously from its creeping root system. The stems are coated in short white hairs. The leaves are made up of many oval leaflets each up to two centimeters long. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a raceme
Raceme
A raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
of several pea-like flowers each just over a centimeter wide. They may be brick-red to deep pink to brownish or red-orange in color. The fruit is a legume pod up to 3.5 centimeters long. It is inflated and bladderlike, hairless, translucent, shiny, and papery when dry. It is mottled greenish or reddish. It contains several seeds each about two millimeters long.
Like other legumes, this plant contains endophyte
Endophyte
An endophyte is an endosymbiont, often a bacterium or fungus, that lives within a plant for at least part of its life without causing apparent disease. Endophytes are ubiquitous and have been found in all the species of plants studied to date; however, most of these endophyte/plant relationships...
s. These include the bacterium Paracoccus sphaerophysae, which was recently isolated from the roots of this species, and named for it. Other rhizobia
Rhizobia
Rhizobia are soil bacteria that fix nitrogen after becoming established inside root nodules of legumes . Rhizobia require a plant host; they cannot independently fix nitrogen...
in this species include Shinella kummerowiae and species of the genera Rhizobium
Rhizobium
Rhizobium is a genus of Gram-negative soil bacteria that fix nitrogen. Rhizobium forms an endosymbiotic nitrogen fixing association with roots of legumes and Parasponia....
, Agrobacterium
Agrobacterium
Agrobacterium is a genus of Gram-negative bacteria established by H. J. Conn that uses horizontal gene transfer to cause tumors in plants. Agrobacterium tumefaciens is the most commonly studied species in this genus...
, and Mesorhizobium
Mesorhizobium
Mesorhizobium is a genus of Gram-negative soil bacteria. At least one, the nitrogen fixing species, Mesorhizobium loti, forms symbiotic root nodules with plants in the genus Lotus. Strain MAFF303099 of M. loti has been fully sequenced....
.