Terry O'Brien and Diana Horton
Abstract—The genus Bryochenea is evaluated by a study of morphological characters from type and other herbarium specimens. The type species, B. ciliata, is taxonomically synonymous with Cyrto-hypnum vestitissimum; therefore, Bryochenea is synonymous with Cyrto-hypnum. Bryochenea sachalinensis, the only other species, has been treated as Helodium sachalinense by most authors. An evaluation of the generic and familial positions of B. sachalinensis, based on comparisons with Helodium and 12 other hypnalean genera, indicates that B. sachalinensis is sufficiently distinct to warrant generic rank. A monotypic genus, Echinophyllum, is described and the new combination, E. sachalinensis, is made. The combination of dry branch leaves that are catenulate, short and strongly unipapillose leaf cells, and lanceolate pseudoparaphyllia with laciniate margins and papillose basal cells support inclusion of Echinophyllum in the Thuidiaceae; however, the elongate paraphyllial cells and elongate apical cells of branch leaves are incongruent with Thuidiaceae and instead suggest closer affinity to Helodiaceae, Hylocomiaceae, or Leskeaceae. The closest match among these alternatives is with Helodiaceae, but there are sufficient differences in habitat, leaf areolation, and pseudoparaphyllia that the alignment with Thuidiaceae is considered preferable.