HYPNUM HESELERI SP. NOV. (HYPNACEAE), A CURIOUS NEW MOSS FROM EUROPE

Abstract

  Hypnum heseleri sp. nov. (Hypnaceae) is described based on an epiphytic specimen collected in Saarland, Germany. The same species is recorded also from two localities in the Netherlands. This moss is remarkably unusual for the genus Hypnum, being characterized by the julaceous habit reminiscent of Myurella julacea, broadly ovate, wrinkled leaves with short twisted acumens, deeply plicate lamina consisting of rhomboidal to broadly linear cells, sinuose subentire margins of leaves, and comparatively large perichaetial leaves with once to thrice twisted acumens. It is most closely related to Hypnum cupressiforme in which an abnormal form with broadly ovate, crisped leaves that mimics this new species is rarely found.