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 fungus, fungi, including their genetics, genetic and biochemistry, biochemical properties, their Taxonomy (biology), taxonomy and ethnomycology, their use to humans, including as a so ...

. 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 the ...

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 munici ...

, 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 fro ...

, Brazil. Following his return to Europe he continued his studies in Valkenburg and

Innsbruck Innsbruck (; bar, Innschbruck, label=Bavarian language, Austro-Bavarian ) is the capital of Tyrol (state), Tyrol and the List of cities and towns in Austria, fifth-largest city in Austria. On the Inn (river), River Inn, at its junction with the ...

, 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 mana ...

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'' (placem ...

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) *'' Des ...

and

Polystomellaceae The Polystomellaceae are a family of fungi with an uncertain taxonomic placement in the class Dothideomycetes Dothideomycetes is the largest and most diverse class of ascomycete fungi. It comprises 11 orders 90 families, 1300 genera and over ...

. The genus '' Theissenia'' was named after him by

André Maublanc André Pierre Jules Maublanc (24 July 1880, in Nantes – 30 April 1958, in Paris) was a French mycologist and plant pathologist. Beginning in 1902, he worked as a préparateur at the Station de Pathologie végétale in Paris. In 1912, he traveled ...

(1914).

Selected writings

* ''Fragmenta brasilica'' (5 parts, 1908–12) in '' Annales Mycologici''. * ''Die Hypocreaceen von Rio Grande do Sul, Südbrasilien'' (1911) in ''Annales Mycologici'' –

Hypocreaceae The Hypocreaceae are a family (biology), family within the class Sordariomycetes. Species of Hypocreaceae are usually recognized by their brightly colored, perithecial Ascocarp, ascomata, typically yellow, orange or red. The family was proposed b ...

Rio Grande do Sul Rio Grande do Sul (, , ; "Great River of the South") is a Federative units of Brazil, state in the South Region, Brazil, southern region of Brazil. It is the Federative_units_of_Brazil#List, fifth-most-populous state and the List of Brazilian st ...

, 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'' and ''

Seynesia ''Seynesia'' is a genus of fungi in the family Cainiaceae. The genus was circumscribed by Pier Andrea Saccardo in Syll. Fungorum vol.2 on page 668 in 1883. The genus name of ''Seynesia'' is in honour of Jules de Seynes (1833–1912), who was a F ...

''. * ''Lembosia-Studien'' (1913) – ''

Lembosia ''Lembosia'' is a genus of fungi in the Asterinaceae family. The relationship of this taxon to other taxa within the class is unknown (''incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relati ...

'' studies. * ''Dothideazeen-Studien'' (2 parts, 1914; with Hans Sydow) in ''Annales Mycologici'' –

Dothideaceae The ''Dothideaceae'' are a family of fungi in the order Dothideales. Species in this family have a widespread distribution, especially in tropical areas. Genera As accepted by Species Fungorum ''Index Fungorum'' is an international project to ...

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 loc ...

. * ''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'' *'' Bot ...

''. * ''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