On the identity of a little-known Riccia species, Riccia wichurae (Ricciaceae) from Japan

Abstract

  Detailed morphological descriptions of a little-known Japanese species, Riccia wichurae Steph. are given based on the type specimen. SEM images of the spores are also provided for the first time. The species is mainly characterized by 0.6–1.0 mm wide thalli with deep median grooves, lacking air chambers, purple or hyaline ventral scales, and large spore size (75–)80–90(–100) μm with irregular thickened wing margins. The author proposes that the species should be treated as a synonym of R. beyrichiana Hampe ex Lehm. which is widely distributed in Japan.