General Characteristics of Clover
Clover is the common name for plants of the genus Trifolium. The scientific name is derived from the Latin words tres ("three") and folium ("leaf"), since most species in the genus have trifoliolate leaves, that is, those composed of three leaflets. Trifolium belongs to the family Fabaceae, in the order Fabales, class Magnoliopsida. The term clover is also used as part of the common name for some trifoliolate-leafed plants that are closely related to Trifolium clovers.
True clovers are herbaceous annual or perennial plants that thrive under cool, moist conditions. Many annual species of clover behave as winter annuals (they germinate in the fall and live through winter) in areas with mild, moist winters and as summer annuals at northern latitudes and high elevations. Perennial clovers persist best at more northern or southern latitudes or at higher elevations. Some species, especially those from Africa, lack winterhardiness.
Clovers are dicotyledonous (the embryo plant has two seed leaves, or cotyledons). The germinating seedling characteristically produces a taproot and, in sequence, the two cotyledons, a unifoliolate (one-leaflet) leaf, and the first of many trifoliolate leaves.
All true clovers have flowers in dense clusters (heads) and one or a few seeds per seed pod. Taxonomy (classification) of species is based on the structure of flowers and seed pods. Flowering occurs only under proper conditions of growth, photoperiod (relative proportions of daylight and dark), and temperature. Flower colors vary from white to yellow to pink, red, and purple and include the intermediate shades. The number of flowers (florets) per flowering head varies from 3 to 200, depending on the species.
Species of clover may be self- or cross-fertilized. Cross-pollination is by insects, mostly bumblebees and honeybees. Clover seeds, depending on the species, vary greatly in size, and seed color ranges from pale yellow to purple to black.
Clovers are grown alone or in combination with other legumes or grasses and are used for hay, pasture, soilage (green fodder), silage (fermented fodder), and soil fertility and for conservation purposes. Establishment (seeding and cultivation) of plants in culture is in early spring or fall, depending on climatic conditions and competition with weeds. Methods of culture and harvest are similar to those of most small-seeded forage legumes.