The essence of all things

2 November 2015

The largest object is a peach stone lying next to cereal grains, tiny grape pips, and the seeds of wild herbs. At first glance, the Archaeobotanical Reference Collection of the Pre- and Protohistoric Archaeology division at the Department of Ancient Studies at Johannes Gutenberg University Mainz (JGU) seems anything but impressive. But as Dr. Margarethe König begins to tell of the stories and history that form its background, it is becoming more and more interesting.

The tiny dark pips Dr. Margarethe König removes from the cardboard box labeled with the number 8 do not look particularly interesting. They are stored in a plastic bag bearing a sticker that provides their Latin nomenclature: Vitis silvestris. The pips are from wild grapes and there is nothing prepossessing about these grape pips. But it soon turns out that they have a whole new and more fascinating side.

Everyone knows that the Romans brought viticulture to Germania. "But were the grape vines transported as plants over the Alps or were they bred from the local wild vines? We already had wild grapes growing here long before the Romans first appeared although they grew rather like lianas in riverside woodland." The grapes matured in the forest canopy. "They were difficult to get to and the fruits were also very small and sour."

So it seems more likely that the Romans imported the vines and that the areas planted with cultivated grapes gradually expanded bit by bit. "But how did the vines arrive here? Did they come via the Belfort Gap into the Mosel Valley? That seems perfectly possible."

4,000 specimens

König stands in front of a cabinet in her office in the Pre- and Protohistoric Archaeology division of the Department of Ancient Studies at Mainz University. The cabinet contains the department's entire Archaeobotanical Reference Collection. "The collection is at the heart of our archaeobotanical work," she says. On benches next to the cabinet are several microscopes under whose lenses even grape pips become massive objects.

It was in 1986 that König, who had studied forestry and geobotany, began establishing an archaeobotanical research unit at the Trier Landesmuseum. She subsequently moved to Mainz University in 2006 and took the seeds, kernels, and grains with her. Her collection has since grown to some 4,000 items.

However, it does not include specimens from past eras. König collects her materials from modern botanic gardens. When she displays a peach stone, which is the largest of the items in the collection, it comes more or less from the present. "The appearance of seeds and kernels has generally remained unchanged over thousands of years," König explains. "The only thing that changes is their size."

König can thus compare a peach stone from an archaeological dig with her kernels to determine the precise species while its size, on the other hand, can be used to determine how effectively growers domesticated the peach back then. The Romans were the true pioneers in the case of peaches, which they also introduced to Germania, and other cultivated plants such as cereals and legumes.

Foreign fruits

"The Romans also brought us the walnut and the sweet chestnut," adds König, continuing the list of things that the Romans imported a long time ago. And those are just the start. The botanist once examined the Roman graveyard located in what is now Mainz-Weisenau. "There we found the stones and seeds of olives, dates, and figs." This was quite remarkable in view of the fact that the cultivation of these plants north of the Alps is impossible or at least extremely difficult because of the climate. "The Romans imported the food their soldiers were used to eating. They knew that any legionary from the Mediterranean region might well consider mutiny if he was fed with just dry barley groats."

Even rice kernels have been found on the site of a Roman military camp near present-day Neuss. "At that time, rice was only being cultivated in India." It must have involved enormous effort and expense to ship it to Germania. "However, centuries before Napoleon, the Romans were already well aware that 'an army marches on its stomach'."

König examines small details to uncover the greater context. "Our purpose is to uncover all aspects of how people once lived." Seeds, grains, and kernels are of considerable help as they provide a record of trade and agriculture. They tell us what people once put on their tables and even provide insight into the origins of those who sat at those tables. The Germanic tribe living at the mouth of the River Main would have been astonished by the variety of exotic foods consumed by those foreigners in their fortification on the heights.

Finest structural details

Even the tiniest fragments provide information although determination is needed to get at it. "A lot of the specimens I get are carbonized." A flax seed will burst like popcorn in a fire. "That, of course, means that it will no longer be in its original form." However, the fine surface structures remain intact.

König displays an illustrated volume produced by a Dutchman, Willem Beijerinck. It is a reprint of an edition of his book published in 1943. The book is filled with black and white drawings of seeds and kernels, showing even the slightest surface furrows. Her shelves are packed with modern reference works containing digitally processed photos and images recorded using scanning electron microscopes but it is still the book by the old Dutchman that is used most frequently. "When I have a difficult specimen, I draw it myself," says König. "That makes me look at it as closely as possible."

The diversity in König's cabinet is amazing. It contains more than just cultivated plants. "Wild herbs often provide more information than wheat or rye, for example. Fields in previous eras were not as uniform as those of today, they generally contained a far greater variety of plants." Their prevalence provides the botanist with information on climate and soil quality and also on the intensity with which agriculture was being undertaken.

Right now she is working on a selection of cereal grains originating from the Celtic Otzenhausen site in Saarland. The grains are 2,200 years old. "We found very few weeds among them." Apparently quite a bit of effort went into the harvest. "Such quality is surprising."

A history of cereals

As König continues to talk about seeds and kernels, she takes us on an excursion through a vast array of subjects and epochs and jumps from period to period. For instance, as far back as the Stone Age it would seem, people were already trying to minimize the risk associated with agriculture. "So they always planted an assortment of different species." Barley, spelt, and emmer were the primary cereals in the Iron Age.

By means of careful cultivation, the Romans absolutely transformed their food plants. Their wheat grains were particularly large. So did grain size then shrink as the Roman Empire crumbled and the Romans' agricultural skills vanished into the mists of time? "No," says König. "People switched to rye in the Middle Ages because it was easier to grow."

The Archaeobotanical Reference Collection is primarily used for research. "We also offer seminars, internships, and continuing education courses. Ancient history societies often contact us with queries." Those who see the small tubes and envelopes containing the tiny seeds, grains, and kernels for the first time may well be disappointed. But König will make sure that they rapidly change their minds. It is only when examined in close-up that the seeds and kernels reveal their significance.