Horsetails are plants in Pikmin 2 for the Nintendo GameCube. It is brown stiffly sticks that pop out of the ground, kind of like posts. It is rarely seen, you can see it at Awakening Wood, and underground in Hole of Beasts.
"This variety of horsetail is prevalent in regions with low nutrient content in the soil. Unlike most other plants, this particular species propagates itself through the release of spores."
"Remove and discard the primitive, scaly leaves, then blanch the tender stock in a buttery broth."