The most major difference between Apricorns and Berries is in the use of the fruit. While Berries can be used in and outside battle by a Pokémon, an Apricorn's outer skin is far too tough for it to be eaten by a Pokémon. Instead, they must first be blended into juice. Usually, Apricorns are hollowed out by specialists and fitted with special devices to be used to catch Pokémon. One such specialist, Kurt, lives in Azalea Town with his granddaughter, Maizie, who assists him in his work.
The special Poké Balls made from Apricorns are unique, quite rare, and often valuable for a Trainer to have on hand in battle. This is due to the fragile nature of Apricorn trees, which may die if too many Apricorns are picked at once or before they are mature enough. Only one Apricorn may be picked per tree per day, in order to prevent harm to it.
The group of Apricorn trees on Route 37 in Generation IV
In times gone by, the only Poké Balls that existed were made from Apricorns, with the process used to create the Poké Balls being developed sometime between 400 and 700 years before the present day in all Pokémon canons. As they were the only Poké Balls at the time, Apricorn Balls were quite common, unlike in modern times, when large companies such as Silph Co. and the Devon Corporation develop Poké Balls mechanically and mass-produce them for use by Trainers.
A black Apricorn. It has a scent beyond one's experience.
Note: Formatted as Blk Apricorn prior to Generation VI
Differences between generations
The group of Apricorn trees on Route 37 in Generation II
While Apricorns have retained their properties between the five games in which they are available, the most major tweak to them has been their availability. In all Generation II games, only one of each is available per day, from the Apricorn trees on Routes37 and 42 and in Azalea Town. In Crystal Version, Kurt is able to make more than one Apricorn Ball per day, if he is given multiple Apricorns of the same color.
The return of Apricorns in HeartGold and SoulSilver Versions solves much of the problem of their availability, with all trees containing the Generation II Berries now having Apricorns growing instead, with some now doubled up, with two trees, rather than one, in some areas. The problem of holding them when they are found is also remedied, as they no longer are placed in the Bag's items pocket, but instead in the Apricorn Box, a Key Item that acts much in the same way that the Berry Pouch did in Pokémon FireRed and LeafGreen.
The Apricorn Box
While Apricorns and the Poké Balls that are made from them can be held by a Pokémon in Generation II, this is not allowed in the Generation IV remakes, as these items are not programmed into the other games of that generation. However, a Pokémon caught in an Apricorn Ball can be traded into Diamond, Pearl or Platinum, but the Ball will appear as a plain Poké Ball for as long as that Pokémon remains in the Sinnoh-based game.
Apricorns can further be used in Generation IV, a side effect of their increased availability. In this generation, the seven can be mixed together into special drinks for Pokémon with an Apriblender, which improve a Pokémon's performance in the various Pokéathlon competitions. Much like Berries, the color of the Apricorns roughly matches up to their flavor and to the Performance stat that they enhance.
In the anime
Apricorns have only appeared once in the anime, in Going Apricorn!. In this episode, Kurt helped Ash, Misty, and Brock to harvest Apricorns, making Poké Balls from the three White Apricorns, two Blue Apricorns, and one Black Apricorn that were found and giving Brock, Misty, and Ash each a Fast Ball, Brock a Heavy Ball, and Ash and Misty each a Lure Ball for later use.
While Apricorns themselves have not been seen since, all three characters who received one caught a Pokémon each with an Apricorn Ball, with Brock using his Fast Ball on a Pineco, Ash and Misty using their Lure Balls on a Totodile and subsequently fighting over the custody of it, and Misty later using hers alone on a Corsola. Presumably, Ash and Misty still have their unused Fast Balls, and Brock still has his unused Heavy Ball. Another Heavy Ball, likely also made by Kurt, was used in Gulpin it Down, though it was not Brock's.
Both the Lure Balls containing Ash's Totodile and Misty's Corsola as well as the Fast Ball containing Brock's Forretress were often erroneously shown as plain Poké Balls in episodes of the anime, though more often than not the correct Poké Ball was shown, especially after the switch to digital coloring.
A White Apricorn
A Pink Apricorn
A Black Apricorn
A Blue Apricorn
In the manga
An Apricorn in Pokémon Adventures
In the Pokémon Adventures manga
Apricorns were first mentioned in Teddiursa's Picnic, in which Kurt used various Apricorns to make special Poké Balls. Gold attempted and failed to eat the fruit of an Apricorn. Apricorns were later mentioned in Out-Odding Oddish, in which Gold was seen running after adding Apricorns into the Apriblender so the Apricorns would mix to make Aprijuice.
Trivia
Grn Apricorn's tree on Route 30 respawning at midnight
The word Apricorn may be a combination of "apricot" and "acorn". "Bonguri" may come from the Japanese chestnut, known as にほんぐり (nihonguri), or from the acorn, どんぐり (donguri).
A woman in the Azalea TownPokémon Center mentions that before Poké Balls became standardized, everyone used hollowed-out Apricorns to capture Pokémon.
Apricorns have sprites for the Apricorn Case as well as in-Bag sprites, which are only used in the point-exchange menu in the Pokéathlon Dome.
In Generation IV, Green Apricorns are by far the most common, appearing in eight places. White and Red Apricorns are tied for the rarest, each only appearing in three places.
In Generation II, all Apricorns can only be found in one place.
In the anime, possibly as a coloring error, Black Apricorns were portrayed as being brown-colored.
Because of the length of the word "Apricorn", only the Red Apricorn is able to have its full color name, with the other six being forced to have abbreviated versions due to an item name's 12-character limit (including spaces). In Japanese, only the Green Apricorn is unable to have a full color name due to the length of "ぼんぐり", as みど mido is an abbreviated form of みどり midori, green.
In Generation VI, due to the being able to have longer item names, the Apricorns are all spelled out in full in English, despite being unobtainable. However, the Green Apricorn's Japanese name remains the same.
In Generation IV, if an Apricorn tree is left bare and on-screen without turning the game off over midnight, the plant will sparkle (in the same way Berry plants do when advancing a stage) and an Apricorn will appear on it. If the game was in sleep mode (the Nintendo DS was closed) over midnight, this will happen as soon as the game is taken out of sleep mode.