Unripened, small buds of the caper bush, typically pickled. When pickled, they are salty and tangy in flavor.
The Mediterranean region of Europe.
Capers have become popular in many European cuisines, traveling broadly with Spanish, French, Italian, and Greek foods.
In the past, people used nasturtium seeds as an alternative to capers when they were not available.
The Diner’s Dictionary Word Origins of Food and Drink 2nd ed. By John Atyo (2012)
“Health Benefits of Capers” reviewed by Dan Brennan (2020) https://www.webmd.com/diet/health-benefits-capers#2
“What Are Capers?” by Danilo Alfaro (2019) https://www.thespruceeats.com/what-are capers-p2-995595