Thallus erect to 15 cm long, fan-shaped with the monostromatic lamina deeply divided into long narrow branches 3 - 10 mm wide and pointed. These branch with irregular small dentations or teeth, some hooked and sickle-shaped. Only microscopic veins present, macroscopic veins are never present. Cryptopleura ramosa
may appear similar but the hooks are marginal rather than marginal and terminal and the veins are only microscopic.