[2][3] The only species, Zanardinia typus, commonly known as penny weed,[4] is native to the northeastern Atlantic Ocean and the Mediterranean Sea.

The genus name of Zanardinia is in honour of Giovanni Antonio Maria Zanardini (1804–1878), who was an Italian physician and botanist who specialized in the field of phycology.

Young individuals are circular and have a smooth surface and a double fringe of short hairs round the margin.

Portions that become detached and wash up on the shore may crinkle as they dry and resemble pieces of blackish leather.

It grows on rock and silty boulders in the shallow subtidal zone at depths down to about 20 m (66 ft).