Mustards are several plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 in the genera Brassica

Brassica

Brassica is a genus of plants in the mustard family . The members of the genus may be collectively known either as cabbages, or as mustards...

and Sinapis

Sinapis

Sinapis is a genus of plants in the family Brassicaceae. One of the species in this genus is White mustard . Black mustard is sometimes placed in this genus as well, but is more often placed in the related genus Brassica...

whose small mustard seed

Mustard seed

Mustard seeds are the small round seeds of various mustard plants. The seeds are usually about 1 or 2 mm in diameter. Mustard seeds may be colored from yellowish white to black. They are important spices in many regional foods. The seeds can come from three different plants: black mustard , brown...

s are used as a spice

Spice

A spice is a dried seed, fruit, root, bark, or vegetative substance used in nutritionally insignificant quantities as a food additive for flavor, color, or as a preservative that kills harmful bacteria or prevents their growth. It may be used to flavour a dish or to hide other flavours...

 and, by grinding and mixing them with water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

, vinegar

Vinegar

Vinegar is a liquid substance consisting mainly of acetic acid and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. Commercial vinegar is produced either by fast or slow fermentation processes. Slow methods generally are used with traditional...

 or other liquids, are turned into the condiment

Condiment

A condiment is an edible substance, such as sauce or seasoning, added to food to impart a particular flavor, enhance its flavor, or in some cultures, to complement the dish. Many condiments are available packaged in single-serving sachets , like mustard or ketchup, particularly when supplied with...

 known as mustard

Mustard (condiment)

Mustard is a condiment made from the seeds of a mustard plant...

 or prepared mustard. The seeds are also pressed to make mustard oil

Mustard oil

The term mustard oil is used for three different oils that are made from mustard seeds:*A fatty vegetable oil resulting from pressing the seeds,...

, and the edible leaves

Leaf vegetable

Leaf vegetables, also called potherbs, green vegetables, greens, leafy greens or salad greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots...

 can be eaten as mustard greens

Brassica juncea

Brassica juncea, also known as mustard greens, Indian mustard, Chinese mustard, and leaf mustard, is a species of mustard plant. Subvarieties include southern giant curled mustard, which resembles a headless cabbage such as kale, but with a distinct horseradish-mustard flavor...

.
Mild white mustard (Sinapis hirta

White Mustard

White mustard is an annual plant of the family Brassicaceae. It is sometimes also referred to as Brassica alba or B. hirta...

) grows wild in North Africa

North Africa

North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...

, the Middle East

Middle East

The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...

 and Mediterranean Europe, and has spread farther by long cultivation; oriental mustard (Brassica juncea

Brassica juncea

Brassica juncea, also known as mustard greens, Indian mustard, Chinese mustard, and leaf mustard, is a species of mustard plant. Subvarieties include southern giant curled mustard, which resembles a headless cabbage such as kale, but with a distinct horseradish-mustard flavor...

), originally from the foothills of the Himalaya, is grown commercially in Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, the UK

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, Denmark

Denmark

Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...

 and the US

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

; black mustard (Brassica nigra

Brassica nigra

Brassica nigra is an annual weedy plant cultivated for its seeds, which are commonly used as a spice.-Description:...

) is grown in Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

, Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

, the US

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and some European countries.