Sunseed Berry

The Sunseed Berry is a treasure found in Pikmin 2 and Pikmin 4, and a fruit in Pikmin 3. It is a regular. In Pikmin 2, it is found on the Awakening Wood, while in Pikmin 3, there are four of them: three in the Garden of Hope and one in the Distant Tundra. In Pikmin 4, it is found in the Sun-Speckled Terrace, the Seafloor Resort, and the Cavern for a King.

Collecting the treasure in Pikmin 2
The Sunseed Berry is found sitting on a ledge just across from the landing site in Awakening Wood, and can be quite easily obtained. It is guarded only by a single Red Bulborb and two Dwarf Red Bulborbs. The ledge is low enough that any type of Pikmin can be thrown up to collect the treasure. Alternately, you can go around to the path that leads to the Snagret Hole and obtain it from there, but this is more time consuming, dangerous, and overall impractical.

Brittany's crash site
This Sunseed Berry is on a ledge next to Brittany's crash site, and is the very first fruit found in the game. It acts as a tutorial for fruit collecting, and will be obtained naturally during said tutorial. Defeat the Bulborb on the path back to the ship to ensure a safe recovery.

Lakeside
Another Sunseed Berry is on a ledge by a pile of fragments used to build an orange bridge. It is recommended to let the bridge be built before the fruit is carried, as it will reach the S.S. Drake much faster. Be sure to defeat the Skutterchucks nearby (or alternatively break all of their crystals), as they may launch the nearby crystal nodules at your Pikmin.

Underwater
Another Sunseed Berry in the Garden of Hope is underwater, past the large cinderblock that the Hocotatian blows up late into the game. It is near a dirt wall. It is protected by several Puckering Blinnows, which should be defeated so the Pikmin can safely carry the fruit.

Distant Tundra
In the Distant Tundra, the only Sunseed Berry is inside one member of a duo of Pyroclasmic Slooches, which are in an enclosed area sealed off by a crystal wall. Along the way back there is a Joustmite and a Bearded Amprat; defeat these as well to ensure the Pikmin have a safe route back to the ship.

Sun-Speckled Terrace
The Sunseed Berry is on top of a small ledge in the central area of the map in the Sun-Speckled Terrace, close to the Rugged Scaffold base. To get to it, Oatchi must be able to jump. Once near it, it can be collected simply by throwing 3 Pikmin up the ledge, or knocking it down with a rush from Oatchi.

Seafloor Resort
There is a Sunseed Berry sitting on top of a tall ledge on the far eastern side of sublevel 1 of the Seafloor Resort. It is blocked by the sprinkler system, so you must either build and turn the clay valve in the upper left corner, or bring only Blue Pikmin with you. To collect this treasure, jump into the geyser north of it, then throw 3 Pikmin at it.

Cavern for a King
There is a Sunseed Berry lying inside of a half-broken pail in the northwestern corner of sublevel 19 of the Cavern for a King, next to a Juicy Gaggle. To collect this treasure, you must throw 3 Pikmin at it.

Golden Sunseed
Golden Sunseeds are fruits found in Mission Mode, Bingo Battle, and the Side Stories in. They are a golden variety of Sunseed Berries, and are thus very valuable, being worth 200 Pokos. Aside from being worth four times as much as Sunseed Berries, they are functionally identical to their regular counterparts. According to a loading screen tip, they are packed with Piktamin U.

Trivia

 * There is an unripe Sunseed Berry in the Garden of Hope on a branch next to where the first Sunseed Berry is found, but it never grows across the course of the game.
 * The first trailer released for Pikmin shows Yellow Pikmin returning a similar strawberry to their Onion.
 * In the E3 2012 demo of Pikmin 3, Golden Sunseeds were referred to as Combustion Berries, a treasure from Pikmin 2.
 * The first strawberry being next to Brittany might reference how strawberries originated from Brittany, France.

Names in other languages
Sunseed Berry

Golden Sunseed