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Herbaria almost as fascinating as its discoverers

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As I continue my exploration of herbariums throughout the Middle East, I chatted some more with Hagar Lesch, the collections manager at the Hebrew University in Jerusalem.

My last question to Hagar was, “What is the most scientifically important specimen in the herbarium?” That took us quickly to an herbarium sheet, which had a grassy-looking specimen.

Today’s food supply derived from plants tends to depend on several major crops from a small number of species. The danger is obvious. When a new disease or pest attacks a particular crop, it can destroy massive amounts of foodstuffs quickly with deadly results. 

This dependence on a single crop caused the Irish Potato Famine between 1845 and 1852 when potato tubers, infested with the mold Phytophthora infestans, caused a million deaths from starvation in Ireland, with another million emigrating out of a country that had a total population of 8 million.

Somewhat later, first reported in 1868, the French wine industry was decimated in a destruction of French vines known as the Great French Wine Blight. In this case, the damage was caused by an aphid, Daktulosphaira vitifoliae, otherwise known as the grape phylloxera. This was an American insect against which American vines had developed resistance. French vines, however, were defenseless. 

The eventual solution was to graft French vines onto American rootstocks.

More contemporaneous, and therefore more cause for concern, is the sudden reappearance of fungal wheat rust diseases. While fungicides can protect plants, large outbreaks could threaten the billion people who depend on wheat as a major foodstuff. First observed in 2016 in Sicily, it is being closely monitored by various governmental agencies.

All of this digression brings us back to the particularly important herbarium sheet. From the above three cases of significant crop failure, it is clearly important to have measures in place to protect the world’s food supply. To this end, there is a serious effort to maintain seed banks with multiple versions — different species of the same genus — particularly of important crop plants.

Our last case of wheat rusts highlights the need for resistant varieties. One scientific method used to reincorporate protective genes is to crossbreed modern plants with their more distant ancestors.

But, what is the ancestor of modern wheat? There is an ancient version of wheat called “emmer” that has been found in Neolithic sites going back to 17000 B.C. It is not known if those samples were cultivated or simply foraged in the wild. 

But already 10,000 years ago, emmer wheat was cultivated in the Middle East and Mesopotamia. This emmer variety, Triticum dicoccum, a specimen collected by Aaron Aaronsohn, was there right in front of me! It was collected in 1906 and caused a sensation at the time. 

And yes, this strain is resistant to known wheat rusts. 

This discovery made Aaronsohn world-famous, and as a result of a fundraising trip to the United States, he was able to create a research station in Atlit in 1909, also supported by the U.S. Department of Agriculture, where he built up a large collection of geological and botanical specimens as well as an important library.

Like all discoveries, there are many layers. Karl Georg Theodor Kotschy was an Austrian botanist and explorer. In 1855, he made a botanical tour of Egypt, Lebanon and pre-state Israel, where he collected specimens for the University of Vienna. At that time, he collected some wild specimens of barley in the vicinity of Mount Hermon. 

Among the barley grains, there also were a few grains of emmer wheat. 

Friedrich August Koernicke was a German agronomist, whose particular interest was cereal grains, especially wheat. He sent Aaronsohn back to Kotschy’s collection sites to gather further emmer specimens. Aaronsohn then found samples in two locations near Mount Hermon and in Rosh Pina, a town in the upper Galilee. 

Molecular studies have supported the contention that emmer is the “Mother of Wheat.”

Aaronsohn, however, did other important work. During World War I, he was an organizer of Nili, a group of Jews in pre-state Israel who spied for the British against the ruling Ottoman Turks. After the war, he entered politics and died under unclear circumstances when his plane crashed over the English Channel in May 1919.

Leschner pulled out one more sheet containing a specimen of Noeae mucronata or  thorny saltwort. The sheet is less interesting than the collector, Tuvia Kushnir. 

He was a well-known botanist and collector with two flowers named for him — an iris named Iris tuvia and a desert crocus called Colchicum tuviae. This past April, a flower only seen by Kushnir 60 years ago — the Galilee fumitory (Fumaria thuretii Boiss) — was spotted. 

Kushnir was killed during the Israel War of Independence as a member of the legendary Lamed Hey.

Who knew that herbaria would be this exciting?

Have a thought or comment for Sura Jeselsohn? Email her at greenscenesura@gmail.com.

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