This Article Contains information directly from the Pikmin Games. This article is based off of an Enemy/Treasure/Area/Cave/Pikmin/Character from the Pikmin series of Games.
Alternatively, one can use Purple Pikmin to reach it because of the way they are thrown. Run up the shallow root in the centre of the left side of the stump while holding a purple, and release it at the highest point the captain can reach. If done properly, the Pikmin slides up the top of the side of the stump and onto the top, then picks up the treasure.