Clover or trefoil are common names for plants of the genus Trifolium, consisting of about 300 species of flowering plants in the legume or pea family Fabaceae originating in Europe. The genus has a cosmopolitan distribution with highest diversity 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, typically growing up to 30 cm tall. The leaves are trifoliate, monofoil, bifoil, cinquefoil, hexafoil, septfoil, etcetera, 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 and Medicago.
Trifolium repens, the white clover, is a herbaceous perennial plant in the bean family Fabaceae. It is native to Europe, including the British Isles, and central Asia and is one of the most widely cultivated types of clover. It has been widely introduced worldwide as a forage crop, and is now also common in most grassy areas of North America, Australia and New Zealand. The species includes varieties often classed as small, intermediate and large, according to height, which reflects petiole length. The term 'white clover' is applied to the species in general, 'Dutch clover' is often applied to intermediate varieties, and 'ladino clover' is applied to large varieties.
Trifolium pratense, the red clover, is a herbaceous species of flowering plant in the bean family Fabaceae, native to Europe, Western Asia, and northwest Africa, but planted and naturalised in many other regions.
Trifolium arvense, commonly known as the hare's-foot clover, rabbitfoot clover, stone clover or oldfield clover, is a flowering plant in the bean family Fabaceae. This species of clover is native to most of Europe, excluding the Arctic zone, and western Asia, in plain or mid-mountain habitats up to 1,600 metres (5,200 ft) altitude. It grows in dry sandy soils, both acidic and alkaline, soil with dry-mesic conditions and is typically found at the edge of fields, in wastelands, at the side of roads, on sand dunes, and opportunistically in vineyards and orchards when they are not irrigated.
Trifolium wormskioldii is a species of clover. Its common names include cows clover, coast clover, sand clover, seaside clover, springbank clover, and Wormskjold's clover.
Trifolium medium, the zigzag clover, is a flowering plant species in the bean family Fabaceae. It is similar in appearance to red clover, Trifolium pratense, but the leaflets are narrower and have no white markings and the narrow stipules are not bristle-pointed. The species is native to Europe from Britain to the Caucasus.
Trifolium albopurpureum is a species of clover known by the common name rancheria clover.
Trifolium angustifolium is a species of clover known by the common names narrowleaf crimson clover, narrow clover and narrow-leaved clover.
Trifolium barbigerum is a species of clover known by the common name bearded clover.
Trifolium bifidum is a species of clover known by the common names notchleaf clover and pinole clover. It is native to the western United States from Washington to California, where it grows in many types of habitat. It is an annual herb spreading or growing erect in form. It is lightly hairy to hairless in texture. The leaves are made up of oval leaflets 1 to 2 centimeters long, usually with notches in the tips. The inflorescence is a head of flowers up to 1.5 centimeters wide. Each flower has a calyx of sepals that narrow to bristles covered in long hairs. The flower corolla is yellowish, pinkish, or purple and under a centimeter long. The flowers droop on the head as they age.
Trifolium buckwestiorum is a rare species of clover known by the common name Santa Cruz clover.
Trifolium depauperatum is a species of clover known by the common names cowbag clover, poverty clover, and balloon sack clover.
Trifolium fucatum is a species of clover known by the common names bull clover and sour clover. It is native to California and Oregon, where it grows in many types of habitat, becoming common to abundant in some areas. It is an edible species of clover.
Trifolium gracilentum is a species of clover known by the common names pinpoint clover and slender clover. It is native to western North America including the west coast of the United States and northwestern Mexico, where it grows in many types of habitat, including disturbed areas. It is an annual herb growing prostrate to erect in form with mostly hairless or slightly hairy herbage. The leaves are made up of lance-shaped to oval leaflets. The inflorescence is an umbel of flowers that spread out or flex downward. The flowers have pink or purple corollas less than a centimeter long.
Trifolium hirtum is a species of clover known by the common name rose clover. It is native to Europe, Western Asia, and North Africa. It is present elsewhere as an introduced species and it is cultivated as a cover crop and animal fodder. It was introduced to California from Turkey in the 1940s as a forage crop, and today it is a widespread roadside weed there.
Trifolium macraei is a species of clover known by the common names Chilean clover, double-head clover, and MacRae's clover. It has a disjunct distribution, occurring on the coastline of Oregon and California in the United States, as well as in South America. It grows in coastal habitat, such as sand dunes, and disturbed areas. It is an annual herb taking a decumbent or erect form. The leaves are made up of oval leaflets 1 to 2 centimeters in length. The inflorescence is usually made up of two oval or rounded heads of flowers each measuring up to 1.5 centimeters wide. Each flower has a calyx of sepals which taper into densely hairy bristles. The flower corolla is purple or bicolored with white or pink.
Trifolium macrocephalum is a species of clover known by the common name largehead clover.
Trifolium microcephalum is a species of clover known by the common names smallhead clover and small-headed clover.
Trifolium obtusiflorum is a species of clover known by the common name clammy clover. It is native to California in the Peninsular, Transverse, Sierra Nevada, and the California Coast Ranges and Cascade Range into southwestern Oregon.
Trifolium variegatum is a species of clover known by the common name whitetip clover. It is native to western North America from southern Alaska and British Columbia to Baja California, where it occurs in many types of habitat.
