TYPIFICATION OF THE GENERIC DESMID NAME MICRASTERIAS DESMIDIACEAE

Abstract

SummaryHistorical analysis of the various generic concepts of Micrasterias (Desmidiaceae, Zygnemaphyceae) since its original description by C. Agardh in 1827 leads to the following conclusions: 1) the name Micrasterias of C. Agardh, 1827, is not valid since it was published before the starting point for nomenclature in the Desmidiaceae (Ralfs, 1848); 2) the valid generic name is Micrasterias C. Agardh ex Ralfs non Micrasterias Kützing; and 3) M. furcata C. Agardh ex Ralfs non M. furcata C. Agardh must be considered the type species for the genus.Without a doubt, typification is one of the most important problems to be settled in the study of the Desmidiaceae. Lack of nomenclatural types for genera and infrageneric taxa in this family is virtually absolute. Contributing to this lack, among others, are the following: 1) the existence of a late nomenclatural starting point for the family; 2) a frequent negligence of specialists in the family to designate types when describing new taxa; 3) the paucity of taxonomic and nomenclatural revisionary studies in the family; and 4) the relative difficulty of preservation of type specimens of unicellular microscopic freshwater algae.