In this book all the varieties of clover will be discussed that have hitherto been found of any considerable value to the agriculture of America. Varieties that are of but little value to the farmer will be discussed briefly, if discussed at all. The discussions will be conducted from the standpoint of the practical agriculturist rather than from that of the botanist. It is proposed to point out the varieties of clover worthy of cultivation, where and how they ought to be cultivated, and for what uses. =Definition of Clover.=--According to Johnson's Encyclopaedia, clover or trefoil is a plant of the genus _Trifolium_ and the family _Leguminosae_. The Standard Dictionary defines it as any one of several species of plants of the genus _Trifolium_ of the bean family _Leguminosae_. Viewed from the standpoint of the American farmer it may be defined in the collective sense as a family of plants leguminous in character, which are unexcelled in furnishing forage and fodder to domestic animals, and unequaled in the renovating influences which they exert upon land. The term _Trefoil_ is given because the leaves are divided into three leaflets. It is also applied to plants not included in the genus, but belonging to the same order. The true clovers have their flowers collected into roundish or oblong heads and in some instances into cone-shaped spikes. The flowers are small and of several colors in the different varieties, as crimson, scarlet, pink, blue, yellow and white, according to the variety, and some are variously tinted. The stems are herbaceous and not twining. The seeds are inclosed in pods or seed sacks, each of which contains one, two and sometimes, but not often, three or four seeds. The plants have tap roots, and in some varieties these go far down into the subsoil. The roots are also in some varieties considerably branched. =Varieties.=--At least twenty varieties, native or naturalized, are found in Great Britain; more than twelve varieties belong to the United States. The more valuable varieties found in this country have been introduced from Europe, unless it be the small white clover (_Trifolium repens_). Viewed from the standpoint of the agriculturist the varieties that are most generally useful include medium red clover (_Trifolium pratense_), alfalfa (_Medicago sativa_), alsike (_Trifolium hybridum_), mammoth (_Trifolium magnum_), crimson (_Trifolium incarnatum_) and small white (_Trifolium repens_). The varieties which flourish only in the South include the Japan (_Lespedeza striata_) and the burr clover (_Medicago denticulata_). Sweet clover (_Melilotus alba_), sometimes called Bokhara, which will grow equally well North and South, is worthy of attention because of its power to grow under hard conditions, in order to provide honey for bees and to renovate soils. Other varieties may render some service to agriculture, but their value will not compare with that of the varieties named.