Caulerpa taxifolia

Caulerpa taxifolia is a species of seaweed, an alga of the genus Caulerpa. Native to the Indian Ocean, it is widely used ornamentally in aquariums, because it is considered attractive and neat in arrangement, and is easy to establish and care for. The alga has a stem (rhizome) which spreads horizontally just above the seafloor. From this stem grow vertical fern-like pinnae, whose blades are flat like those of the yew (Taxus), hence the species name taxifolia.