Alternanthera Bettzickiana 'Red' commonly known as a Calico Plant. It is a terrarium, vivarium, or bog plant that is sometimes used as aquatic plant decoration even though it's not a true aquatic plant. It has light pink to red stem, green to yellow leaf. When growing in strong light, the leaf will turn to intense red color.
Under a proper environment, it can only be submerged for several months. After that, it should be grown emerged for a few months again so they can restore the energy they lose before it has the ability and strength to adapt and survive to underwater life for a period of time.
Because of the ability to survive underwater for a long period of time, a lot of hobbyists used this plant as an alternative for other true aquatic plants because they claimed it can survive or even grow a few inches taller and develop roots in their aquarium longer than some of the other true aquatic plants.
When grow emerged, above water. It should be kept in a consistent high humid with wet soil. Especially when they are in the recovery stage or when their environment is changed from underwater to above water.