Ernst Vilhelm Østrup was a Danish botanist and phycologist, mainly working on diatoms.
Chaetoceros is probably the largest genus of marine planktonic diatoms with approximately 400 species described, although many of these descriptions are no longer valid. It is often very difficult to distinguish between different Chaetoceros species. Several attempts have been made to restructure this large genus into subgenera and this work is still in progress. However, most of the effort to describe species has been focused in boreal areas, and the genus is cosmopolitan, so there are probably many tropical species still undescribed. Some species are known from the fossil record, from the Quaternary of Sweden. It is the type genus of its family.
Craticula is a genus of diatom that lies on or in the top layers of sediments in the freshwater to brackish water environments it inhabits. In addition to frustule morphology the genus differs from closely related species by its sexual reproduction and movement in response to light.
Amphora is a major genus of marine and freshwater diatoms. With over 1000 species, it is one of the largest genera of diatoms. These diatoms are recognized by their strongly dorsiventral frustules, which means that their ridges lie close to the ventral margin of the valve, and their girdle is much wider on the dorsal side.
Navicula depressa is a freshwater species of algae of in the genus Navicula. Navicula depressa occurs in Fennoscandia.
Navicula cari is a species of algae in the genus Navicula. Navicula cari occur in eutrophic waters.
Stauroneis is a genus of diatoms (Bacillariophyta) with species that occur in fresh and marine water.
Thalassiothrix is a genus of Chromista belonging to the family Thalassionemataceae.
Tolypella is a genus of green algae belonging to the family Characeae.
Achnanthes is a genus of diatoms belonging to the family Achnanthaceae.
Eucapsis is a genus of cyanobacteria belonging to the family Merismopediaceae.
Adlafia is a genus of diatoms belonging to the family Anomoeoneidaceae.
Aneumastus is a genus of diatom belonging to the family Mastogloiaceae.
Caloneis is a genus of diatoms belonging to the family Naviculaceae.
Chamaepinnularia is a genus of diatoms belonging to the family Naviculaceae.
Cosmioneis is a genus of diatoms belonging to the family Cosmioneidaceae.
Diploneis is a genus of diatoms belonging to the family Diploneidaceae.
Gomphocymbella is a genus of diatoms belonging to the family Cymbellaceae.
Gomphonema is a genus of diatoms belonging to the family Gomphonemataceae.
Melosira is a genus of diatoms belonging to the family Melosiraceae.
