Alexander Zahlbruckner

Alexander Zahlbruckner (31 May 1860 – 8 May 1938) was an Austrian botanist and lichenologist who became one of the early 20th century's most influential lichen taxonomists. He spent his career at the Natural History Museum in Vienna, rising from volunteer to First Director (1918–1922). He became a leading authority through extensive fieldwork across the Austrian Alps and collaboration with European herbaria.

Zahlbruckner's most enduring contributions include his comprehensive classification system for lichens, published in Engler and Prantl's work Die Natürlichen Pflanzenfamilien (1903–1926). It organized lichen families primarily by fruiting body morphology and was widely adopted in handbooks across Europe. He also compiled Catalogus lichenum universalis (1921–1940), a ten-volume global catalogue of all known lichen species that imposed order on centuries of chaotic nomenclature and remains a standard reference for historical lichen literature.

His taxonomic work on Asian lichens, particularly his synthesis of Chinese species (1930) based on collections from Tibet and south-west China, introduced hundreds of new taxa and helped lay a foundation for regional lichenology. His annual literature reviews for Just's Botanischer Jahresbericht (1884–1931) and editorial work on specimen exchange series also helped coordinate the international lichen research community for nearly half a century.