THE TYPE FOR FRAGILARIA LANCETTULA SCHUMANN 1867 AND TRANSFER TO THE GENUS PUNCTASTRIATA AS P. LANCETTULA (SCHUM.) HAMILTON & SIVER COMB. NOV.

Abstract

Fragilaria lancettula was described in 1867 by Julius Schumann from freshwater material collected near Königsberg, Prussia. The limited description and presentation of two slightly different original illustrations of the valve form, has created confusion in the literature with published recombinations as varieties under Fragilaria pinnata, Fragilaria mutabilis, and Staurosirell apinnata. With the present examination of Schumann's type material, Fragilaria lancettula is now assigned to the genus Punctastriata with a complete circumscription of the species. This taxon is more common than currently reported and is often associated with Staurosira spp. (including Staurosira construens), Staurosirella pinnata sensu lato, and Pseudostaurosira spp. (including P. elliptica and P. brevistriata).

Keywords:

• Fragilaria lancettula
• fragilarioid diatoms
• Königsberg Prussia
• lectotype
• Pseudostaurosira
• Punctastriata lancettula
• Schumann
• Staurosira
• Staurosirella
• taxonomy