Lychnothamnus (Rupr.) Leonh., Lotos 13: 57, 72 (1863), p.p.

Chara sect. Lychnothamnus Rupr., Beitr. Pflanzenk. Russ. Reiches 3: 11–12 (1845). Type: Lychnothamnus barbatus (Meyen) Leonh.

Monoecious. Plant axis corticated or cortex reduced to a few filaments growing down from the axial nodes. Stipulodes in one whorl (haplostephanous), branchlets ecorticate, bract cells elongate (> 8 mm) and verticillate. Gametangia arranged on the branchlet nodes side-by-side, usually two antheridia with a central oosporangium. Gametangia originating from different initial cells. Helical cells of the oosporangium terminated by a coronula of five cells. Oospores with a calcified covering (gyrogonite).

Lychnothamnus has one species in Europe, with representatives in China (Han and Li 1994), India (Wood and Imahori 1965), the United States (Karol et al. 2017), and several fossil representatives (Martin-Closas and Ramos 2005).