The Stylonematophyceae is one of the morphologically most diverse groups of red algae outside the Florideophyceae, consisting of unicellular (e.g. Rho- dosorus), filamentous (e.g. Stylonema) and blade-like (e.g. Goniotrichopsis) representatives. Sexual reproduc- tion and sexual structures have never been observed in this group. Convincing reports of sexual reproduc- tion outside the Bangiophyceae (e.g. Porphyra) and Florideophyceae are lacking. The only class in which sexual stages have been reported is the Compsopogono- phyceae. Sexual reproduction has also been reported in the Rhodochaetales (Rhodochaete parvula), which has a diplohaplontic life cycle (Magne 1960). Within the Erythropeltidales the genera Chlidophyllon and Pyro- phyllon clearly have sexual structures similar to Por- phyra (Nelson 1993; Nelson et al. 2003), suggesting