Macrocystis
/ˌmakrə(ʊ)ˈsɪstɪs/noun
A genus of brown algae of which the only species now recognized is Macrocystis pyrifera, a giant kelp which is widespread in the southern hemisphere and along the Pacific coast of America; an alga of this genus.
Origin
Mid 19th century; earliest use found in Joseph Hooker (1817–1911), botanist. From scientific Latin Macrocystis from macro- + ancient Greek κύστις bladder.