The Diatom Collection of Franz Josef Weinzierl

The Collection

Franz Josef Weinzierl established his diatom collection in 1919 and maintained it until to his death in 1969. The collection together with his extensive library is now housed at the Botanische Staatssammlung München. Original material and exsiccatae from several diatom specialists worldwide are included. The collection comprises about 2,200 glass vials with vouchers in alcoholic solution, 700 dried specimens and 13,000 microscope slides. The microscope slides are categorized and arranged as A-slides, B-slides, D-slides and E-slides. The A-slide collection includes about 600 slides from the surroundings of Landshut and is the oldest part of the Weinzierl collection. The B-slide collection comprises about 2,500 slides from c. 1,200 localities worldwide (350 localities in Bavaria). These slides contain mixed populations of diatom taxa as collected from one locality and prepared by Franz Josef Weinzierl or other collectors. The B-slides are especially useful for ecological studies. Taxon names are usually not given. The E-slide collection contains about 8,000 slides from c. 900 localities worldwide (170 localities in Bavaria). These slides are special preparations for about 2360 single diatom taxa; they are useful for identification and taxonomic purposes. The D-slides are duplicates. In addition, Franz Josef Weinzierl elaborated detailed records as to the ecology and biodiversity of diatoms from about 2,500 localities worldwide.

The collection as a whole is used as reference collection for the determination of diatoms and has great significance for applied ecological research because of the important part played by diatoms as bioindicators of water-quality. In this respect, the material supplies important information for the poorly documented period of the beginning until the middle of this century.

Due to the excellent documentation for each specimen it is possible to show for a lot of localities – especially in Bavaria –, which diatoms existed there. These data can be compared with present day data, obtained by the Bayerisches Landesamt für Wasserwirtschaft and thus through routine research, differences in the water quality as a consequence of environmental change can be detected. For a more intense use of these data, a database application of Franz Josef Weinzierl´s diatom collection has been constructed as a cooperative project of the Bayerisches Landesamt für Wasserwirtschaft and the Botanische Staatssammlung München.

The Data Project and Service

The Database "The Diatom Collection of Franz Josef Weinzierl" and – if not stated otherwise – its supporting files have been copyrighted © 2001–2024 by the Botanische Staatssammlung München and the Bayerisches Landesamt für Wasserwirtschaft. For non-commercial purposes, permission is given for free use of data in the search result; any commercial use must be granted by prior written agreement.

The data project "The Diatom Collection of Franz Josef Weinzierl" was established by D. Triebel, R. Klee and S. Eichacker. It uses a MS Access Database application, developed by G. Hagedorn and expanded by M. Weiß. The ColdFusion webinterface was programmed by W. Spiesberger and M. Weiß.

Currently, online search options for two different microscope slide collections within "The Diatom Collection of Franz Josef Weinzierl" are available: You may search the so-called B-slides using the geographical region/ country, the collector and/ or the ecosystem (categorized by the colour of the slides) and you may search the so-called E-slides using a taxon name or parts of it, the geographical region/ country, the collector and/ or the ecosystem.

You do not need to add wild cards. The output comprises a scan of the original slide, information on the originally cited taxon name (only for E-slides) as well as locality data (with the locality number in parentheses), collecting dates and it also gives the preparation number of the single slides as for example B 1295 or E 6085.

Actually, the database "The Diatom Collection of Franz Josef Weinzierl" is maintained and expanded as part of the Phycology.Net project.

All entries have been checked for accuracy using a number of information sources. Nevertheless, typing- and other errors may occur. In such cases we kindly ask the user to contact the editorial staff at the Botanische Staatssammlung München.