Life history and taxonomy of two populations of ligulate Desmarestia (Phaeophyceae) from Chile

Abstract
Two populations of broad-bladed (ligulate) Desmarestia from central and southern Chile were studied in laboratory cultures. They differ in sporophyte morphology and gametophyte characters (monoecism versus dioecism). The dioecious population is found to be related to D. firma from South Africa and D. munda from the northeast Pacific, while the taxonomic status of the broad-bladed monoecious population is left undetermined. In both populations sporophytes originate after fertilization as well as by apomixis. Chromosome numbers alternate between ca. 23 and ca. 46. Evidence is presented that spermatozoids of the dioecious Desmarestia can develop into sporophytes (androgenesis or ephebogenesis).