CLOVER (AS. ehefre, trefoil, of unknown origin), or TREFOIL ( Tri/O/ii/ ). A genus of plants of the natural order Leguminosa% suborder Papilionaceir, containing a great number of species, natives chiefly of temperate climates, abounding most of all in Europe, although about sixty species are indigenous to the United States; some of them very important, in agri culture, as affording pasturage and fodder for cattle and as a means for improving cultivated soil. The name 'clover! is also popularly ap plied to certain plants. which have compound leaves with three leaflets like the clovers, and also belong to the order Leguminosa.. but which are not included in the genus Trifolium—sneh as sweet or Bokhara clover (llclilohis). low clover (.11edicago). prairie clover (Petalost e won). bird's-foot clover (Lotus), and a number of others. The true clovers (Trifolium) have herbaceous, not twining stems; roundish heads or oblong spikes of small flowers. the corolla re maining in a withered state till the ripening of the seed; the pod inclosed in the calyx, and con taining one or two. rarely three or four seeds. About seventeen species belong to the flora of Great Britain. The species of most importance to the farmer is the common red clover (Tri folium pro tense). (For illustration, see Plates of DICOTYLEDONS and of Broonnoo-r.) This is a native of America and of most parts of Europe.
growing in meadoWs and pasture. it stands in the front rank of forage plants for good yields, nutritive value, and adaptability to various cli mates and soils. It is a perennial, but is general ly treated as if it were a biennial. Its heads of flowers are oval or nearly globular, very compact, about an inch in diameter, purple, more rarely tlesh-colored or white; the tube of the calyx is downy; the stipules run suddenly into a bristly point. The leaflets have very often a whitish horseshoe mark in the centre. It is supposed that clover found its way into England from the Netherlands about the time of Queen Elizabeth; but it was not until the close of the last century that it was introduced into Scotland, where it is now universally prevalent. Perennial red clover (T,-ifoliuttt protease percnne) is a somewhat hardier form than the ordinary forms of common red clover and of longer duration, lasting for two years or more. The zigzag clover (Tri foliont medium), also called meadow clover, marl-grass, and eow-grass, much resembles the common red clover, but is easily distinguished by the smooth tube of the calyx, and by the broader, less membranaecous, and gradually acu minated stipules. The stems are also remark
ably zigzag. and are more rigid than in Trifolium pratense; the heads of flowers are larger, more lax, more nearly globose. and of a deeper purple color, and the leaflets have no white spot. It is a common plant in Great Britain and most parts of Europe, and is also grown to some ex tent in the United States. White or Dutch clover (Trifoli-am repen0 is also a common native of Great Britain, and of most parts of Europe as well as of North America. When a barren heath is turned up with the spade or plow, white clover almost always appears. It is more permanent than common red clover. and it grows on nearly all soils, hut its yield bi small. \\lite clover is seldom grown alone. but usually in mixtures of grasses and other clover. The flowers of all kinds of clover are the delight of bees, but those of white clover perhaps par ticularly so. Alsike or Swedish clover (Tri folium hyl•idunt), a perennial, regarded as in termediate in appearance between the common red clover and the white clover, was introduced into Great Britain from the south of Sweden in 1834. It is also becoming, common in North America. Crimson clover, or Italian clover (Trifo/ium in•a•natunt), an annual, native of the south of Europe. with oblong or cylindrical spikes of rich crimson flowers. is much cultivated in Continental Europe. and is also pretty exten sively grown in some parts of England and the United States. Moline•'s clover (T•ifo/ium 1/o lineri) very ninth resembles crimson clover, hut is biennial and has pale flowers. It is cultivated in Europe. Alexandrian clover. or Egyptian Mover (Trifolinia .tlexundrilill111), an annual species, a native of Egypt. universally cultivated in its native country. where it is the principal fodder for cattle, is supposed to be one of the best kinds of clover for warm climates—such as, for instance, the Southern United States. it has oval heads of pale-yellow or whitish flowers. Yel lo• clover. or hop-trefoil (Trifoliam procum bens), is common in dry. gravelly soils, but is not much esteemed. It has smaller leaves and flower heads than has any of the cultivated species. The flowers are yellow, and the heads resemble minia ture hop-strohiles.