Tscharna Rayss (1890–1965): Pioneer of Mycology and Phycology
Tscharna Rayss was a foundational figure in the biological sciences of the 20th century, particularly in the Middle East. As a pioneering woman in a male-dominated field, she established the study of "lower plants"—fungi and algae—in Mandatory Palestine and the early State of Israel. Her work bridged the gap between European botanical traditions and the exploration of Levantine biodiversity, leaving an indelible mark on both mycology (the study of fungi) and phycology (the study of algae).
1. Biography: From Bessarabia to Jerusalem
Tscharna Rayss was born on January 26, 1890, in Bershad, in the Bessarabia region of the Russian Empire (modern-day Ukraine/Moldova). Her academic journey began in Switzerland, where she enrolled at the University of Geneva. She studied under the renowned Swiss botanist Robert Chodat, a specialist in algae and fungi. In 1917, she earned her Doctorate of Science with a dissertation on the morphology and cytology of the green alga Coelastrum proboscideum.
Following her graduation, Rayss returned to Eastern Europe. From 1922 to 1934, she served as a researcher and lecturer at the University of Bucharest in Romania. During this period, she established herself as a meticulous taxonomist, focusing on the fungal pathogens affecting crops in the Danube region.
In 1934, motivated by both her Zionist convictions and the rising tide of European antisemitism, Rayss immigrated to Mandatory Palestine. She joined the newly established Hebrew University of Jerusalem (HUJI). Initially appointed as a lecturer in the Department of Botany, she rose through the academic ranks to become a Professor in 1951. She remained at the university until her death on April 4, 1965, in Jerusalem.
2. Major Contributions: Mapping the Invisible Flora
Rayss’s scientific career was defined by her ability to categorize and understand organisms that had previously been ignored in the region.
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Founding Israeli Mycology
Before Rayss, the fungal diversity of the Levant was largely undocumented. She conducted extensive surveys of both wild and parasitic fungi. Her work was not merely academic; it had immense practical value for the burgeoning agricultural sector of the young state, as she identified the pathogens responsible for crop failures in citrus groves and vineyards.
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Marine Phycology and the Red Sea
Rayss was one of the first scientists to systematically study the marine algae of the Mediterranean and Red Sea coasts. She was particularly interested in the "Lessepsian Migration"—the movement of marine species from the Red Sea to the Mediterranean via the Suez Canal. Her documentation of these shifts provided early data on how man-made geographical changes alter biological ecosystems.
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Taxonomic Precision
She was a master of systematics. Throughout her career, she identified and described dozens of new species of fungi and algae, providing a rigorous framework for future researchers to build upon.
3. Notable Publications
Rayss was a prolific writer, publishing over 100 scientific papers in French, German, and Hebrew. Some of her most influential works include:
- Le Coelastrum proboscideum, étude de morphologie et de cytologie (1915): Her doctoral thesis, which remains a classic study in algal cytology.
- Nouvelle contribution à l'étude de la flore mycologique de Palestine (1946–1953): A multi-part series that served as the definitive catalog of fungi in the region.
- Sur les algues marines de la côte palestinienne (1941): This work laid the groundwork for marine biology in the Eastern Mediterranean.
- The Plankton of the Israel Coastal Waters (1950s): A series of studies that analyzed the microscopic base of the marine food web, essential for the fishing industry.
4. Awards & Recognition
While Rayss lived in an era when women were frequently overlooked for major international prizes, her contributions were deeply honored within the scientific community:
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Officier de l'Instruction Publique
This prestigious French decoration was awarded to her for her services to science and education.
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Taxonomic Honors
Several species were named in her honor by colleagues, including the fungal genus Rayssiella and the species Cercospora rayssiae.
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The Rayss Herbarium
The Hebrew University of Jerusalem named its extensive collection of lower plants the "Tscharna Rayss Herbarium" in recognition of her role in collecting and classifying its specimens.
5. Impact & Legacy
Tscharna Rayss’s legacy is preserved in the very landscape of Israeli science. She was one of the "Founding Mothers" of the Hebrew University’s Faculty of Science.
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Educational Influence
She mentored a generation of botanists and plant pathologists who went on to lead Israeli agriculture and environmental conservation efforts.
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The Herbarium
The specimens she collected—often under difficult field conditions—remain a vital resource for modern genomic and ecological research.
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Ecological Baseline
Her early 20th-century surveys provide a "baseline" that allows modern climate scientists to measure how much the Mediterranean and Red Sea environments have changed due to global warming and pollution.
6. Collaborations
Rayss was a highly collaborative researcher who maintained a bridge between European and Middle Eastern science:
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Robert Chodat
Her mentor in Geneva, with whom she maintained a lifelong intellectual connection.
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The "Botanical Triumvirate"
At the Hebrew University, she worked closely with Alexander Eig, Michael Zohary, and Naomi Feinbrun-Dothan. While they focused largely on "higher" vascular plants (flowers, trees), Rayss provided the essential missing piece of the puzzle: the "lower" plants that supported the ecosystem.
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International Marine Biologists
She collaborated with researchers from the French National Museum of Natural History, ensuring that her findings in the Middle East were integrated into global biological databases.
7. Lesser-Known Facts
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Fieldwork at Any Age
Even in her 60s and 70s, Rayss was known for her physical stamina. She would frequently wade into the Mediterranean surf or climb rugged hillsides to collect specimens, often outlasting her younger students.
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A Polyglot Scholar
Rayss was fluent in Russian, French, German, Romanian, and Hebrew. This linguistic range allowed her to act as a scientific ambassador, translating complex European botanical theories for her Hebrew-speaking students.
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A Hidden Artist
Her scientific illustrations were noted for their extreme precision and aesthetic beauty. Before the era of high-resolution micro-photography, her hand-drawn diagrams of fungal spores and algal cells were essential for the identification of species.