Valonia (alga)

Valonia is a genus of green algae, in the Valoniaceae family. The cells have multiple nuclei and many chloroplasts, each with a pyrenoid. The cells of some species are very large, up to 2 cm in diameter. In some species the colonies maintain a symmetrical shape but in others they do not. Some species have been extensively used for studies of ion-exchange and water potential across biological membranes.