Pikmin can be in one of three stages of maturity. The more mature the Pikmin is, the faster it becomes, and the more efficient it is at completing tasks. As such, it is on the player's best interest to keep their Pikmin in high maturity. A Pikmin's stage can be identified by what's on top of its stem, and there are several ways for Pikmin to both increase and decrease in maturity. Three stages exist: leaf, bud, and flower; all Pikmin start in the leaf stage when born. Although Pikmin start their life as a seed, and then a sprout, those stages are separate from maturity, since they already have a leaf when that happens.
When stored into an Onion, Pikmin do not lose their maturity, meaning that the player will not lose flower or bud Pikmin between days. When pulling Pikmin out of an Onion, flower Pikmin come out first, then buds, and finally leaves.
The standby Pikmin icon in the first two games makes the distinction between different maturities of Pikmin. Before throwing in Pikmin 2 and the two New Play Control! remakes, it is possible to swap out a Pikmin on a leader's hand for one of a different maturity within the same type; this can be achieved by pressing / .
Because a higher maturity is better than a lower one, some rankings in the games use icons based on the Pikmin stems' tops to symbolize their value. For instance, in Mission Mode, the bronze medal has a leaf icon, the silver medal has a bud, and the gold and platinum medals have a flower. Analogously, flowers are sometimes depicted in the series as symbols of evolution or idealism, such as the Pikmin 2 Challenge Mode levels on the grid changing to flowers upon completion.
The first, basic stage. A simple green leaf sticks atop the stem. Pikmin in this state are slow and not as effective at completing tasks as other maturities. Newborn Pikmin always start off as leaves.
The second stage. These Pikmin have a round bud on their stem. Pikmin normally have white buds, but Purple and White Pikmin have magenta buds, and Rock and Winged Pikmin have lavender ones. At this maturity, Pikmin have average speed.
The final stage, also called "blossom" by Captain Olimar. Flower Pikmin are the fastest, and have a chaenostoma cordatum atop their stems. In Pikmin, flower Pikmin that die in battle have a chance of leaving behind a sprout that appears the following day. The color of a Pikmin's flower is the same as the color of its bud.
In Pikmin and Pikmin 2, a flower Pikmin twirls horizontally in the air after it reaches the apex of its throw arc. When it does this, it falls down slightly slower than leaf or bud Pikmin. This twirl also makes the Pikmin lose some horizontal momentum, which makes leaf and bud Pikmin fall farther in a throw than Yellow Pikmin. Purple Pikmin do not have this twirl, since they pound after the apex. This maturity difference does not exist in the New Play Control! remakes.
The most basic way for Pikmin to increase in level is to let them remain underground for some time without plucking them. As they stay underground, they extract nutrients from the soil, which allows them to evolve from their current stage to the next one every few minutes.
The other common way to have Pikmin mature is to feed them nectar. This will instantly set them to flower status if they are on the leaf or bud stages.
Other ways also exist:
In the first two games, buried flower Pikmin wither and disappear if left underground for too long, but do eventually return as a leaf, where the cycle repeats. Interestingly, in Pikmin 3, buried Pikmin will not be able to evolve past leaf stage on the first day, nor on Brittany's section of the first Distant Tundra day, presumably because both of these events do not have time periods and players would thus be able to wait until the Pikmin become flowers without consequence. In Pikmin 3, Pikmin that are buried and far from the player will also not evolve, probably because they are off camera; their maturation timer only moves when the player is close to them.
In Pikmin and Pikmin 2, Pikmin only evolve if the leader is in the same area they are, and if the gameplay is playing. This means that if the player returns to a buried leaf Pikmin some day later, they will not find a flower Pikmin, regardless if the day with the leaf Pikmin was ended with the pause menu or not. In Pikmin 3 though, this was changed so that Pikmin that stay buried overnight will evolve to the flower stage, and since buried Pikmin in the flower stage do not revert like in the previous games, leaving buried Pikmin overnight is a good way to evolve them. This is also true if the player ends the day early from the pause menu (even if the Pikmin don't appear as flowers in the sunset cutscene), and works regardless of how long during the day the buried Pikmin has been left.
In all games, buried Pikmin take 2 minutes to advance in stage. In Pikmin and Pikmin 2, once a buried Pikmin reaches the flower stage, it stays that way for 3 minutes, where it eventually wilts and disappears; it stays as a flower forever in Pikmin 3. After wilting, a Pikmin takes 1 minute to return as a leaf in Pikmin, but only 8 seconds in Pikmin 2.
There are some ways for Pikmin to decrease in maturity in the first two games. Pikmin in Pikmin 3 will never lose their stage to a weaker one.
A "rebirth" via a Candypop Bud could be considered a way for a Pikmin's status to revert back to a leaf, and this is true for every game, although technically, the Pikmin that gets tossed in disappears and a new one is born in its place.
In alternative game modes
In Bingo Battle, a Pikmin's leaf or flower is the same color as the team it's on – cyan for player 1, and pink for player 2. In both 2-Player Battle and Bingo Battle, maturity does not have an impact on what Pikmin will win a fight when Pikmin are attacking each other. Also to note is that in Bingo Battle, it is not possible to get bud Pikmin because they cannot evolve if they are left underground, but this is not true in Pikmin 2's 2-Player Battle mode.
In Hey! Pikmin
In Hey! Pikmin, maturity is bound to the number of Pikmin under Olimar's command in the current area. This is only for aesthetics and does not affect the gameplay. Pikmin mature in three stages; leaf, bud and flower. Pikmin start off as leaf and grow buds when there are eight Pikmin under Olimar's command. These buds bloom into flowers when there are sixteen Pikmin under Olimar's command. Wild Pikmin are always in the leaf stage and will automatically convert to the stage in Olimar's team when connected. Losing Pikmin can result in their maturity downgrading.
Pikmin in the Pikmin Park have maturities picked at random, and once again, these do not affect the performance of the Pikmin, and are just for show.
In other media
In the Pikmin Short Movies
The Pikmin Short Movies portray Pikmin changing maturity in ways that do not coincide with the canon games. While at times the change in maturity is mostly a visual gag, there are situations where the evolutions have an impact on the outcome of the story.
In Treasure in a Bottle, the Pikmin outside of the bottle change from leaf to flowers when they come up with an idea. This is likely a take on the cartoon joke where characters that come up with ideas receive a glowing lightbulb on top of their heads.
Near the end of Occupational Hazards, when the Pikmin and Bulborb are falling from the backhoe's bucket, the Pikmin's leaves turn into flowers, serving as parachutes. When Yellow Pikmin touch the backhoe's battery, their leaves turn into buds, which is something that does not happen in Pikmin 3; when they finish the circuit, their buds stay the same, whereas in the third Pikmin game, finishing a circuit rewards all Pikmin involved with a flower status. A Red Pikmin can also be seen evolving into a flower after emerging from the mud, in the scene after the Fiery Blowhog is defeated, but the reason for this is not known.
In addition to this, in the opening to The Night Juicer, some mature Purple Pikmin have erroneously white-colored flowers. However, this was most likely done for the sake of having the Pikmin logo, which they help form, all white.
In the Super Smash Bros. series
In the Super Smash Bros. series, the Pikmin following Olimar start on the leaf stage when plucked, and slowly evolve into buds and then flowers as they stay on the battlefield. This change is only aesthetic, though, although it is the main concept behind event #14: "Sproutage of the Flower Pikmin", in Brawl. To save on performance, Pikmin always stay on the leaf status in Super Smash Bros. for Nintendo 3DS.
In Pikmin Adventure
In the Nintendo Land attraction Pikmin Adventure, Olimar players and Pikmin players may collect blobs of nectar to increase a numeric level. Three drops of nectar are needed to increase one level, and between levels 1 and 4, that player's Pikmin will be in the leaf stage. Between levels 5 and 9, the bud stage, and from 10 onward, the flower stage. Although the maturity itself has no impact on the Pikmin's performance, the numeric level does. The Olimar player also receives an increase in Pikmin number when evolving to a new stage.