Clover or trefoil are common names for plants of the genus (Trifolium, Latin, tres "three"+folium "leaf"), consisting of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes on mountains in the tropics. They are small annual, biennial, or short-lived perennial herbaceous plants.
Clover, either sown alone or in mixture with ryegrass, has for a long time formed a staple crop for silaging, for several reasons: it grows freely, shooting up again after repeated mowings; it produces an abundant crop; it is palatable to and nutritious for livestock; it fixes nitrogen, reducing the need for synthetic fertilizers; it grows in a great range of soils and climates; and it is appropriate for either pasturage or green composting.