Trachynema, a new genus in the Punctariaceae (Fucophyceae)

Two little known species of brown algae, Litosiphon mortensenii S. Lund and L. groenlandicus S. Lund, described from East Greenland have been compared with the type species of the genera Litosiphon Harv. and Asperococcus Lamour. They are distinguished from the genus Litosiphon by their basally sheathed hairs, hecatonematoid microthalli, mediate differentiation of embryospores, and lack of sympodial branching of the macrothallus. They are considered more primitive than Asperococcus by the absence of paraphyses and by the non-localized formation of reproductive structures. The new genus Trachynema is proposed to accommodate these plants; it finds a natural position in the Punctariaceae.