Ferdinand Theissen (27 July 1877 in

Krefeld Krefeld ( , ; li, Krieëvel ), also spelled Crefeld until 1925 (though the spelling was still being used in British papers throughout the Second World War), is a city in North Rhine-Westphalia, Germany. It is located northwest of Düsseldorf, i ...

– 5 September 1919) was a German-Austrian

Jesuit priest , image = Ihs-logo.svg , image_size = 175px , caption = ChristogramOfficial seal of the Jesuits , abbreviation = SJ , nickname = Jesuits , formation = , founders = ...

and

mycologist Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans, including as a source for tinder, traditional medicine, food, and entheogens, as w ...

. He studied

theology Theology is the systematic study of the nature of the divine and, more broadly, of religious belief. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of analyzing th ...

at the seminary in

Feldkirch Feldkirch may refer to: Places * Feldkirch, Vorarlberg, a medieval city and capital of an administrative district in Austria ** Feldkirch (district), an administrative division of Vorarlberg, Austria * Feldkirch (Hartheim), a village in the municip ...

, then from 1902 to 1908 was stationed in

São Leopoldo São Leopoldo () (Portuguese for ''Saint Leopold'') is a Brazilian industrial city located in the south state of Rio Grande do Sul. Geography It occupies a total area of 103.9 km² (around 80 km² urban area) at ''circa'' 30 km fr ...

, Brazil. Following his return to Europe he continued his studies in Valkenburg and Innsbruck, and in 1914 returned to Feldkirch as a schoolteacher. He died in September 1919 as a result of a climbing accident during a collection excursion in the Vorarlberg Alps. He was the author or co-author of numerous mycological taxa; with

Hans Sydow Hans Sydow (29 January 1879 – 6 June 1946) was a German mycologist and the son of mycologist and lichenologist, Paul Sydow (1851–1925). Career Hans Sydow worked at the Dresdner Bank in Berlin between 1904 and 1937 rising to divisional man ...

he co-described the families

Botryosphaeriaceae The Botryosphaeriaceae are a family of sac fungi (Ascomycetes), which is the type representative of the order Botryosphaeriales. According to a 2008 estimate, the family contains 26 genera and over 1500 species. Members of this order include not ...

Dothioraceae The Dothioraceae are a family of fungi in the order Dothideales. Species in this family have a widespread distribution, and are biotrophic or necrotrophic, usually associated with woody plants. Genera *''Aureobasidium'' *'' Botryochora'' (pla ...

Phyllachoraceae Phyllachoraceae is a family of sac fungi. Genera As accepted by 2020 Outline (with amount of species per genus); *''Ascovaginospora'' (1) *'' Brobdingnagia'' (4) *'' Camarotella'' (8) *'' Coccodiella'' (27) *''Cyclodomus'' (5) *'' Desh ...

and Polystomellaceae. The genus ''

Theissenia ''Theissenia'' is a genus of fungi in the family Graphostromataceae. The genus was circumscribed by André Maublanc in Bull. Soc. Mycol. France vol.30 on page 51 in 1914. The genus name of ''Theissenia'' is in honour of Ferdinand Theissen (1877� ...

'' was named after him by André Maublanc (1914).

Selected writings

* ''Fragmenta brasilica'' (5 parts, 1908–12) in ''

Annales Mycologici ''Sydowia'' is a biannual peer-reviewed scientific journal covering the study of fungi, including their taxonomy, systematics, evolution, structure, development, ecology, pathology in plants, animals, and humans, and biotechnological applicat ...

''. * ''Die Hypocreaceen von Rio Grande do Sul, Südbrasilien'' (1911) in ''Annales Mycologici'' –

Hypocreaceae The Hypocreaceae are a family within the class Sordariomycetes. Species of Hypocreaceae are usually recognized by their brightly colored, perithecial ascomata, typically yellow, orange or red. The family was proposed by Giuseppe De Notaris in 184 ...

of Rio Grande do Sul, southern Brazil. * ''Decades Fungorum Brasiliensium'', (1911). It is an exsiccata-like work. * ''Le genre Asterinella'' (1912) – The genus '' Asterinella''. * ''Zur Revision der Gattungen Microthyrium und Seynesia'' (1912–13) in ''Österreichische Botanische Zeitschrift'' – Revision of the genera ''

Microthyrium ''Microthyrium'' is a genus of fungi in the Microthyriaceae family. Species As accepted by Species Fungorum; * '' Microthyrium aberrans'' * '' Microthyrium abnorme'' * '' Microthyrium acaciae'' * '' Microthyrium annuliforme'' * '' Microthyr ...

'' and '' Seynesia''. * ''Lembosia-Studien'' (1913) – '' Lembosia'' studies. * ''Dothideazeen-Studien'' (2 parts, 1914; with Hans Sydow) in ''Annales Mycologici'' – Dothideaceae studies. * ''Die Dothideales. Kritisch-systematisch Originaluntersuchungen'' (1915; with Hans Sydow) in ''Annales Mycologici'' – The

Dothideales Dothideales are an order of bitunicate fungi consisting mainly of saprobic or plant parasitic species. Description Taxa in this order are characterized by the absence of a hamathecium (defined as hyphae or other tissues between asci) in a locul ...

. * ''Studie über Botryosphaeria'' (1916) in ''Annales Mycologici'' – Studies of the genus ''

Botryosphaeria ''Botryosphaeria'' is a genus of pathogenic fungi in the family Botryosphaeriaceae. There are 193 species, many of which are important disease-causing agents of various important agricultural crops. Species *''Botryosphaeria abietina'' *''Botry ...

''. * ''Die Gattung Parodiella'', (1917) in ''Annales Mycologici'' – The genus ''Parodiella''.Cybertruffle
(List of scientific papers)

References and notes

{{DEFAULTSORT:Theissen, Ferdinand 1877 births 1919 deaths People from Krefeld German mycologists Austrian mycologists 20th-century German Jesuits Jesuit scientists