Ezo epiyessoense, a new parasitic genus and species of Corallinaceae (Rhodophyta, Cryptonemiales)

Ezo epiyessoense, a new parasitic genus and species of Lithophylloideae, and its host Lithophyllum yessoense are described. The parasitic plants are small, colourless, develop host-penetrating haustoria and, compared to their hosts, possess smaller conceptacles, slightly smaller cells and thinner epithallia. However, E. epiyessoense and L. yessoense are alike in having single-layered hypothallia and secondary pits. Also, the reproductive structures are quite similar. It is suggested that E. epiyessoense is an adelphoparasite, as is the melobesioid parasite Kvaleya epilaeve.