Sargassum johnsonii Sargassum johnsonii Sargassum johnsonii Chapman, 1961, is a brown seaweed of the genus "Sargassum" that is endemic to the Three Kings Islands in New Zealand. It is sometimes called totara weed because of the resemblance to the foliage of the NZ native tree totara. Its scientific name derives from its discoverer, Magnus Earle Johnson, Three Kings Islands explorer and captain of the yacht "Rosemary", who landed botanists on the islands on several occasions. "Sargassum johnsonii" grows in rocky intertidal habitats, often extending to the subtidal zone up to a depth of 40 m. It is a foundation species, and being
Sargassum develop in the axils of leafy laminae. It is self-fertile. In summer 2015, large quantities of different species of "Sargassum" accumulated along the shores of many of the countries on the Caribbean Sea. Some of the affected islands and regions include the Caribbean coast of Mexico, the Dominican Republic, Barbados, and Tobago. Another large outbreak occurred in 2018. The algae wash ashore, pile up on beaches, and decay, often causing a foul odor, releasing fumes of sulphur compounds that rust metals, can turn taps black in shore houses, damage modern conveniences, and cause respiratory problems, particularly for asthmatics. A doctor