 A 1980 survey of McDonald Island found lower diversity than that on Heard Island; four mosses and a number of algal species are recorded from there.At least 100 species of terrestrial algae are known from Heard Island, commonly in permanently moist and ephemeral habitats.Forests of the giant Antarctic kelp "Durvillaea antarctica" occur at a number of sites around Heard Island and at least 17 other species of seaweed are known, with more to be added following the identification of recent collections.