Taxonomic revision of two rare infraspecific taxa of Tryblionella (Nitzschia) marginulata var. didyma (Bacillariophyceae)

摘要

The following two diatom taxa found in hydrothermal sites of Milos Island (Greece) - both of them representing new records for the Greek diatom flora - have been revised: (i) Nitzschia marginulata f. elongata is transferred herein as Tryblionella marginulata f. elongata comb. nov., its diagnosis is emended, its nomenclatural history is outlined and its biogeography is provided, and (ii) Nitzschia marginulata f. parva is transferred herein as Tiyblionella marginulata f. parva comb. nov., its diagnosis is emended, taxonomic comments are given and its biogeography is provided.