The Bitter Vetch (Vicia ervilia) is an ancient grain legume crop of the Mediterranean region. Besides the English name, other common names include: Gavdaneh (Persian), kersannah (Arabic), yero (Spanish), rovi (Greek), and burçak (Turkish). The nutritional value of the grain for ruminant production has guaranteed the continued cultivation of V. ervilia in Morocco, Spain and Turkey. The crop is easy to cultivate and harvest and can be grown on very shallow, alkaline soils.
Bitter vetch grain when split resembles red lentils. For human consumption the bitterness of the seeds needs to be removed through leaching by several changes of boiling water. Owing to this bitterness, it is unlikely that someone would accidentally confuse bitter vetch with red lentils. According to Zohary and Hopf, only humans of the poorest economic classes consume this crop, or in times of famine; however, Pliny the Elder states that bitter vetch (ervum) has medicinal value like vetch (vicia), citing the letters of Augustus where the Emperor wrote that he regained his health from a diet of bitter vetch (N.H. 18.38).
The grain is an excellent sheep and cattle feed concentrate. It has been held in high esteem by farmers in the Old World since the beginning of agriculture to improve the nutritional value of bulk feeds.
The wild strains of bitter vetch are limited to an area that includes Anatolia and northern Iraq, with an extension south along the Anti-Lebanon Mountains of Lebanon. Traces of the earliest domesticated instances were recovered from several archeological sites in Turkey, which have an uncorrected Radiocarbon dating of the 7th and 6th millennia BC.
Use By Humans[]
Bitter Vetch (V. ervilia) is one of the first domesticated crops. It was grown in the Near East about 9,500 years ago, starting perhaps even one or two millennia earlier during the Pre-Pottery Neolithic A. By the time of the Central European Linear Pottery culture – about 7,000 years ago –, Broad Bean (V. faba) had also been domesticated. Vetch has been found at Neolithic and Eneolithic sites in Bulgaria, Hungary and Slovakia. And at the same time, at the opposite end of Eurasia, the Hoabinhian people also utilized the Broad Bean in their path towards agriculture, as shown by the seeds found in Spirit Cave, Thailand.
Though Bernard of Clairvaux shared bread of vetch meal with his monks during the famine of 1124-26, an emblem of humility, eventually the Bitter Vetch was dropped from human use, save as a crop of last resort in times of starvation: vetches "featured in the frugal diet of the poor until the eighteenth century, and even reappeared on the black market in the South of France during the Second World War", Maguelonne Toussaint-Samat, of Marseillais background, has remarked. Broad Beans remained prominent though, be it in the Near East where the seeds are mentioned in Hittite and Ancient Egyptian sources dating from more than 3,000 years ago as well as in the Bible or in the large Celtic Oppidum of Manching from La Tène Europe some 2,200 years ago. Dishes resembling ful medames are attested in the Jerusalem Talmud which was compiled before 400 AD.
In our time, the Common Vetch (V. sativa) has also risen to prominence. Together with Broad Bean cultivars such as Horse Bean or Field Bean, the FAO includes it among the 11 most important pulses in the world. It is grown – like Tufted Vetch (V. cracca) – as a mid-summer pollen source for honeybees, but the main usage of the Common Vetch is as forage for ruminant animals, both as fodder and legume. The Bitter Vetch, too, is grown extensively for this purpose, as are Hairy Vetch (V. villosa, also called Fodder Vetch), Bard Vetch (V. articulataHornem.), French Vetch (V. serratifolia) and Narbon Bean (V. narbonensis). V. benghalensis and Hungarian Vetch (V. pannonica) are cultivated for forage and green manure.
The Hairy Vetch also has well-established uses as green manure and allelopathic cover crop. As regards the Broad Bean, it is known to be a accumulate aluminium in its tissue; on polluted soils it may be useful in phytoremediation but with one permil aluminium in the dry plant (possibly more in the seeds) might not be edible anymore. The robust plants are useful as a beetle bank to provide habitat and shelter for carnivorous beetles and other arthropods to keep down pest invertebrates. When the root nodules of Broad Bean are inoculated with the rhodospirillacean bacterium Azospirillum brasilense and the glomeracean fungus Glomus clarum, the species can also be productively grown in salt-\. In the 1980s, the auxin 4-Cl-IAA was studied in V. amurensis and the Broad Bean, and since 1990, the antibacterial γ-thionins fabatin-1 and -2 have been isolated from the latter species.
Despite a small chromosome count of n6, the Broad Bean has a high DNA content, making it easy for a micronucleus test of its root tips to recognize genotoxic compounds. A lectin from V. graminea is used to test for the medically significant N blood group.
Toxicity[]
The vetches grown as forage are generally toxic to non-ruminants (such as humans), at least if eaten in quantity. Cattle and horses have been poisoned by V. villosa and V. benghalensis, two species that contain canavanine in their seeds. Canavanine, a toxic analogue of the amino acid arginine, has been identified in Hairy Vetch as an appetite suppressant for monogastric animals, while Narbon Bean contains the quicker-acting but weaker γ-glutamyl-S-ethenylcysteine . In Common Vetch, γ-glutamyl-β-cyanoalanine has been found. The active part of this molecule is β-cyanoalanine. It inhibits the conversion of the sulfur amino acid methionine to cysteine. Cystathionine, an intermediary product of this biochemical pathway is secreted in urine . This process can effectively lead to the depletion of vital protective reserves of the sulfur amino acid cysteine and thereby making Vicia sativa seed a dangerous component in mixture with other toxin sources. The Spanish pulse mix comuña contains Common Vetch and Bitter Vetch in addition to vetchling (Lathyrus cicera) seeds; it can be fed in small quantities to ruminants, but its use as a staple food will cause lathyrism even in these animals. Moreover, Common Vetch as well as Broad Bean – and probably other species of Vicia too – contain oxidants like convicine, isouramil, divicine and vicine in quantities sufficient to lower glutathione levels in G6PD-deficient persons to cause favism disease. At least Broad Beans also contain the lectin phytohemagglutinin and are somewhat poisonous if eaten raw. Split Common Vetch seeds resemble split red lentils (Lens culinaris), and has been occasionally mislabelled as such by exporters or importers to be sold for human consumption. In some countries where lentils are highly popular – e.g. Bangladesh, Egypt, India and Pakistan – import bans on suspect produce have been established to prevent these potentially harmful scams