Robert Hegnauer, PhD, botanist, phytochemist, and pharmacognosist, passed away on April 14, 2007, at the age of 87.¹ Author of the famous Chemotaxonomie der Pflanzen (Chemotaxonomy of Plants), Dr. Hegnauer approached botanicals in a way that was then unprecedented; that is, through the analysis of plants’ chemical compounds and phylogenetical classification of their genera and families.² However, this uniquely valuable resource was printed only in German.

Dr. Hegnauer was born in Aarau, Switzerland (near Bern) in 1919.^2,3 He received his PhD in 1948 from the world-renowned Eidgenössische Technische Hochschule (ETH), or the Swiss Federal Institute of Technology in Zürich, after studying under the famous Professor H. Flück. Starting in 1949, he served as a research assistant at the Institute of Pharmacy at Leiden University in the Netherlands, and at the age of 33 (1952), he was appointed a full professor of pharmacognosy. In 1962 he switched to the Institute of Pharmacy and Biology where he became a professor of experimental plant systematics.³

The Chemotaxonomie der Pflanzen volumes were published from 1962 to 2001 and comprised over 10,000 pages. Dr. Hegnauer wrote the majority of these pages after he retired in 1979. In these volumes he compiled the phytochemical data of plants, discussed their taxonomic impact, their variations in taxa, their biochemical pathways, and their biological functions, all without the use of online databases, according to Adolf Nahrstedt in a Planta Medica article.⁴ It has been said that Dr. Hegnauer’s wife, Minie Hegnauer-Vogelenzang, co-wrote the four last volumes, but according to her this is not true. “I did the type-writing but Robert wrote all volumes by hand, word after word,” wrote Minie Hegnauer (written communication, November 28, 2007).

Dr. Hegnauer was awarded the Egon-Stahl-Award in Gold in 1999, the highest honor of the Gesellschaft für Arzneipflanzenforschung (GA), or the Society for Medicinal Plant Research.² Dr. Hegnauer received the Fluckiger Medal of the Fluckiger Foundation in 1977 and the Silver medal of the Phytochemical Society of Europe in 1987. He was an Honorary Member of the American Society of Pharmacognosy (ASP), GA, and Deutsche Botanische Gesellschaft (DBG), or the German Botanical Society. He also received honorary doctorates from ETH Zürich, and the University of Utrecht in the Netherlands, bringing his PhD count to 3. However, many veterans in the world of natural chemistry agree that he was more than an author and a scientist with doctorates.

“Robert’s most stand-out qualities were his unpretentiousness, his honesty, and his readiness to help—not only in a scientific way, but above all in a human way,” wrote Minie Hegnauer. “He tried to help everyone as much as he could— whenever it was necessary—which is why my children and I loved him so very much.”

“In spite of all his successes and honors, Professor Hegnauer was always of reserved politeness, open minded, non-biased, fair, and honest,” wrote Prof. Nahrstedt.⁴ “With his broad knowledge and critical sense he has stimulated many young and older scientists. [His] loss will be deeply felt in the world of plant sciences; we will miss him as a friend and faithful academic fellow; he will live on in his life’s work and our commemoration.”

Dr. Hegnauer is survived by his wife and his 3 children Hanneli, Evert, and Fritz.