Clover

Clover ( Trifolium ), or trefoil , is a genus of about 300 species of plants in the 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. The leaves are trifoliate (rarely 5- or 7-foliate), with stipules adnate to the leaf-stalk, and heads or dense spikes of small red, purple, white, or yellow flowers; the small, few-seeded pods are enclosed in the calyx .

Other closely related genera often called clovers include Melilotus ( sweet clover ) and Medicago ( alfalfa or 'calvary clover'). The " shamrock " of popular iconography is sometimes considered to be young clover.

The scientific name derives from the Latin tres , "three", and folium , "leaf", so called from the characteristic form of the leaf, which has three leaflets (trifoliate); hence the popular name trefoil . Clovers are used as food plants by the larvae of some Lepidoptera ( butterfly and moth ) species;