Umeboshi (Japanese: 梅干; literally "dried ume") are pickled ume fruits. Ume is a species of fruit-bearing tree in the genus Prunus, which is often called a plum but is actually more closely related to the apricot. Umeboshi are a type of tsukemono, or traditional Japanese pickled food, and are very popular in Japan. Many Japanese have Umeboshi for breakfast or lunch.
Umeboshi are usually round, and vary from unwrinkled to very wrinkled. They taste salty, and are extremely sour due to high citric acid content – they have been known to corrode their way through aluminium lunch boxes if kept in the same spot every day.
Umeboshi are often cited in Japan as being extremely healthy. The standard Japanese folk remedy for colds and flus is okayu (Japanese congee) with umeboshi.
The central area of Wakayama prefecture is known throughout Japan for the number and quality of its ume and umeboshi. The town of Minabe, Wakayama, in particular, grows more ume and produces more umeboshi than any other town in all of Japan.