Vicia sativa

Vicia sativa, known as the common vetch, garden vetch, tare or simply vetch, is a nitrogen-fixing leguminous plant in the family Fabaceae. Although considered a weed when found growing in a cultivated grainfield, this hardy plant is often grown as green manure or livestock fodder. Vicia sativa is a sprawling annual herb, with hollow, four-sided, hairless to sparsely hairy stems which can reach two meters in maximum length. The leaves are stipulate, alternate and compound, each made up of 3–8 opposite pairs of linear, lance-shaped, oblong, or wedge-shaped, needle-tipped leaflets up to 35 millimetres (1.4 in) long. Each compound leaf ends in a branched tendril. The pea-like flowers occur in the leaf axils, solitary or in pairs. The flower corolla is 1–3 centimetres (0.4–1.2 in) long and bright pink-purple in colour, more rarely whitish or yellow. The flowers are mostly visited by bumblebees. The fruit is a legume pod up to 6 or 7 centimeters long, which is hairy when new, smooth later, then brown or black when ripe. It contains 4–12 seeds. Sown for fodder, the seed is sown densely, up to 250 kg per hectare. However, when grown for seed, less seed should be used; otherwise the crop will be too thick, reducing flower and seed production. When meant for seed, sowing is done early in the planting season for good returns; but, when for green manure, any time in spring is suitable. Sometimes, a full crop can be obtained even when sown as late as summer, though sowing so late is not recommended. After the seed is sown and the land carefully harrowed, a light roller ought to be drawn across, to smooth the surface and permit the scythe to work without interruption. Also, the field should be watched for several days to prevent pigeons from eating too much of the sown seed. Horses thrive very well on common vetch, even better than on clover and rye grass; the same applies to fattening cattle, which feed faster on vetch than on most grasses or other edible plants. Danger often arises from livestock eating too much vetch, especially when podded; colics and other stomach disorders are apt to be produced by the excessive amounts devoured.