Astronomer (1839-1919).
Gustav Niessl von Mayendorf (26 April 1839 in Verona – 1 September 1919 in Hütteldorf, Vienna; often cited as G. von Niessl), was an astronomer and mycologist from Austria-Hungary. Niessl developed interests in botany, astronomy, and mathematics from a young age. His academic career began in 1859 as an assistant professor at the polytechnic institute in Brno, where he later became a full professor and served as rector (1877–1878). As an astronomer, he conducted research on meteor orbits that earned him membership in the Austrian Academy of Sciences, while his mycological work focused on micro