Mermaid's Wineglass

Mermaid's wineglass is a genus of green algae, Acetabularia, in the family Polyphysaceae, typically found in subtropical waters. It is a single-celled organism that is nonetheless gigantic in size and complex in form, making it an important model organism for studying cell biology; a mature individual resembles the round leaf of a nasturtium, stands four to ten centimeters tall, and has a rhizoid base, a long stalk, and a top umbrella of branches that may fuse into a cap. Unlike other giant single-celled organisms, which have many nuclei, members of this genus have a single nucleus located in the rhizoid, which lets the cell regenerate completely if its cap is removed.