Ulota panchengiana, a new species from China and notes on the taxonomy of U. morrisonensis Horik. & Nog. (Orthotrichaceae)

Ulota panchengiana Q.H.Wang & Y.Jia is described and illustrated as a new species from China. It is characterized by both stomata that are scattered throughout the urn and by naked calyptra, two remarkable characters that are rarely found in Ulota species from the northern Hemisphere. Ulota panchengiana is easily recognized by the combination of the following characters: lanceolate leaves with an ovate base, the presence of a few rows of hyaline cells at the basal leaf margin, and long seta. The ecology, geographical distribution, variation, and morphological comparison with related taxa are discussed. Ulota morrisonensis, endemic to Taiwan, is easily misidentified as U. crispa. However, based on a study of an isotype of the former species and in response to a recent reevaluation of the circumscription of U. crispa, we confirm its rank as a species and discuss obvious morphological differences between the two species. A revised key to Chinese Ulota species is provided.