|Snail Bean (Vigna caracalla)|
Numerous, see text
The genus Vigna is in the plant family Fabaceae. The genus is named after Dominico Vigna, an Italian botanist of the 17th century. They include some well-known and other less well-known beans formerly — and sometimes still, especially in non-scholarly sources — included in the genus Phaseolus. Common names in this genus reflect its mixed taxonomic history: some are referred to as "peas" and others as "beans". The Urad Bean (V. mungo) is sometimes called a "lentil", while germinating Mung Bean (V. radiata) are often sold as bean sprouts similar to those of the Soybean (Glycine max).
Many Vigna species are cultivated for food. Indeed, the genus contains most of the important legumes in subtropical and tropical regions; Vigna can be considered the equivalent of the Phaseolus beans predominant in temperate climates, though if anything even more important. Their foliage is also suitable as livestock fodder, and by fixing nitrogen from the air, they improve the soil and are often seen in intercropping with cereals such as millets. It has even turned out that mashed cowpea seeds can be used as coagulants in solar water disinfection. Such is the importance of Vigna in tropical agriculture that for example the Ganda clan eMpindi ("The Cowpeas") takes its totemic name from V. unguiculata, not from an animal or some attribute reflecting strength or vigour.
The Cowpea was established as a model organism in plant genetics by J. B. S. Haldane, and eventually became an important object of study in molecular biology. Cowpea proteins that have been studied include for example a germination-related gamma thionin, inositol 4-methyltransferase and RNA uridylyltransferase.
Vigna species are used as food plants by the caterpillare of some Lepidoptera species, including the Turnip Moth (Agrotis segetum) and the Gram Blue (Euchrysops cnejus). Mexican Bean Beetle (Epilachna varivestis) larvae also feed on Vigna species. A significant parasitic plant affecting the Cowpea is Cowpea Witchweed (Striga gesnerioides), an unusual member of the genus Striga as these plants typically parasitize grasses. And finally, there are some plant viruses that can be devastating to Vigna cultures, such as the Alternanthera mosaic virus, Groundnut crinkle virus and White clover mosaic virus, which are all Flexiviridae, and the Vigna sinensis mosaic virus, which is a rhabdovirus.
Formerly placed here was for example the Hyacinth Bean (Lablab purpureus), as Vigna aristata.
Classification System: APG II (down to family level)
Cladus: core eudicots
Cladus: Eurosids I
Species: V. aconitifolia - V. adenantha - V. ambacensis - V. angivensis - V. angularis - V. antillana - V. candida - V. caracalla - V. comosa - V. dalzelliana - V. decipiens - V. desmodioides - V. elegans - V. filicaulis - V. friesiorum - V. frutescens - V. gazensis - V. glabrescens - V. gracilis - V. heterophylla - V. hispida - V. hosei - V. juncea - V. khandalensis - V. kirkii - V. lanceolata - V. lasiocarpa - V. laurentii - V. linearis - V. lobatifolia - V. longifolia - V. luteola - V. marina - V. membranacea - V. minima - V. monophylla - V. multiflora - V. multinervis - V. mungo - V. nakashimae - V. nervosa - V. nigritia - V. nuda - V. oblongifolia - V. o-wahuensis - V. parkeri - V. peduncularis - V. pilosa - V. pygmaea - V. racemosa - V. radiata - V. reflexopilosa - V. reticulata - V. sandwicensis - V. schimperi - V. speciosa - V. spectabilis - V. stenoloba - V. subterranea - V. trilobata - V. triphylla - V. truxilensis - V. umbellata - V. unguiculata - V. venulosa - V. verticillata - V. vexillata - V. wittei