The gherkin, Cucumis sativus, is a fruit similar in form and nutritional value to a cucumber.
Gherkins and cucumbers belong to the same species but are different cultivar groups.
They are usually picked when 4 to 8 cm (1 to 3 in) in length and pickled in jars or cans with vinegar (often flavoured with herbs, particularly dill; hence, "dill pickle") or brine to resemble a pickled cucumber.
Gherkins are believed to have been the first ever pickle and were enjoyed 4500 years ago in Mesopotamia.
Cleopatra was a fan of pickles, as she believed that they would enhance her beauty.
Roman legionnaires and Napoleon's troops all enjoyed their pickles too, and during the Second World War 40% of all pickles produced in the US were earmarked for the Armed Forces.
Pickled gherkins are served to accompany other foods, often in sandwiches.
They were associated with central European and European Jewish cuisine, but are now found more widely.
Sometimes also called a 'cornichon', this is simply the French word for gherkin.