Interpreting waterlogged plant assemblages

Waterlogged plant assemblages may consist of economic plants used by the site's population as well as plant remains from the natural environment of the site, which have not been in a direct contact with man. For the archaeobotanical interpretation it is necessary to distinguish between the two sources. While for cultivated plants this is obvious, this must be validated and discussed for most of the wild plant species.

For that, in a first step the entire assemblage of subfossile wild plant species has to be grouped in ecological groups to reconstruct the different habitats from where they might have come. These habitats must have been at the site itself or within the action scope of the people. A second step is, to study the natural vegetation and the vegetation history at the site. This can be done by botanical-stratigraphical analyses or pollen analyses in drillings or profiles.

In the case of wetland sites, species from moorland, riverside or lakeshore habitats as well as most of the aquatic plant species normally are parts of the natural environment and probably have not been in a direct contact with man. Of course there are exceptions like the water chestnut (Trapa natans) which could be collected as a food plant. In the case of urban or rural dryland sites with waterlogged sediments, remains of ruderal species often are found, that have been growing directly at the site.

On the other hand, plant remains from habitats beyond the site must have been brought in by man or by animals and for that must be considered to have economic aspects. Some of the most important groups are:

1. Woodland, hedges and forest edges. These habitats offer a lot of useful plants like collected wild fruits and nuts like raspberry, strawberry, blackberry, black elder, hazelnut and others. Besides, different medical plants and dye plants grow in these areas. Wood delivers building material and fuel, bark material for different fabrics.

2. Grassland. Remains from fresh and dryer grassland may derive from animal fodder, brought into the site by people or derived from animal dung. Plants from wet meadows could have been used as bedding in stables.

3. Field weeds and ruderals. Uncharred seeds and fruits from field weeds and ruderals may derive directly from crop processing, giving evidence of where in the site these activities were performed. On the other hand they might have been discarded on rubbish heaps, in wells or at other places.

Economic aspects of some important tissue types


Cereal Bran

Bran has mostly been found in cesspits, latrines and human coprolites as well as in cultural layers where it proves, that cereal products have been eaten. The size of the fragments show how fine the grains have been ground. If well preserved transversal cells exist, information about the ground cereal species may even be available. Bran has also been identified on uncarbonized surfaces of charred porridge. Some porridge crusts have been found at the bottom of neolithic ceramic pots while others showed impressions of bowls of wood or bark.

References among others:

  • Dickson & Dickson 1979
  • Dickson 1989, pl. 1,
  • Greig 1981,
  • Huntley & Hillam 2000,
  • Kenward & Hall 1995, fig. 193,
  • Maier, U. 2001, table 4,
  • Maier, S. 1988, fig. 3

Cereal Chaff

Of great interest are uncharred chaff concentrations still situated where they have been produced, because they may provide important information about plant processing. When cereals are processed, straw as well as free-threshing rachis internodes and a few grains are produced at a first stage. While straw finds are extremely rare in wetland sites, rachis fragments of naked wheats and naked barley are frequently found. A lack of straw proves that it has not been brought into the settlements and that it has not been used as a roofing material or a staple for other purposes (mats, baskets etc). For example for the early neolithic it has been suggested, that cereals were harvested high on the culm without their straw.

Concentrations, or even layers, of uncharred threshing remains of bread wheat, durum wheat or naked barley might indicate threshing places inside the village in prehistoric wetland sites. If they are lacking although carbonized threshing remains are present, this might point to threshing processes outside the settlement.

Glume bases and spikelet forks of glume wheats, sometimes mixed with small quantities of whole spikelets and grain seedcoats, are by-products from a later processing stage (van der Veen 2007, 987). From many sites it has been shown, that the dehusking was usually carried out inside the villages as a daily routine. Such a place of dehusking has probably been discovered in the neolithic settlement of Bad Buchau Torwiesen II.

References among others:

  • Brombacher and Jacomet 1997
  • Jacomet 1989, 92ff., 319,
  • Jacomet et al. 2004, 120ff.,
  • Maier 2001, 54ff.,
  • Maier (in prep.)


The flax plant can be used in two different ways: for its oily, nutritious seeds and for its fibres. Today, the production of linseed is focussed on the Mediterranean region and North Africa while, as a fibre plant flax is still cultivated in Central Europe. In prehistoric times the same plants were used for both purposes, as subfossile macroremains from waterlogged sites show.

The processing of flax is a elabotare and arduous process and each processing stage produces a characteristic product and by-products. At harvesting the plants must be pulled up with their roots because the fibrous stems don’t allow them to be cut. Remains of hypocotyles and roots demonstrate this harvesting method for prehistoric times. The first processing stage was to remove the ripe seed capsules and to thresh them. To separate the broken capsules from the seeds the mixture had then to be winnowed. The by-products of winnowing are masses of capsule fragments with smaller quantities of seeds, which have often been found in waterlogged sediments.

Mixture of capsule fragments and linseeds from the neolithic site Alleshausen-Grundwiesen/Germany. Photo: Ch. Herbig.

For fibre production the stems must be rotted in ponds, ditches or on wet meadows for a couple of days, so that their wooden parts break up and the fibres are released. When the rotting is finished, the stems have to be removed from water, dried and then beaten and broken. The product of this process is the fibres, which are preserved archaeologically in the form of threads, complete fish-nets, textiles and other products. By-products are stem fragments and the stem debris (“shives”), of which sometimes large quantities are found in waterlogged sediments. If these are concentrated in particular parts of a settlement, they may indicate special processing areas.

References among others:

  • Jacomet et al. 1989, 178f.,
  • Jacomet et al. 2004, 124f.,
  • Körber-Grohne 1967, 147ff.,
  • Maier 2001, 68 ff., 199f.,
  • Maier 2004, 105f.,
  • Maier in prep.,
  • Kenward & Hall 1995

Flax-processing with neolithic means - an experiment

Especially in neolithic wetland sites of the alpine foreland, flax was an important crop used as a food plant and as a source for fibres. In archaeological contexts products of flax, like textiles and fish-nets, have been frequently found as well as remains of the different stages of flax processing. Within the archaeobotanical project "Integrated Archaeobotanical Research IAR" at the Department of Archaeology, University of Sheffield, UK, a flax experiment has been carried out together with the "Federsee Museum" in Bad Buchau, Germany in 2008. The whole process from harvesting the plants to producing linseeds and flax fibres should be performed with neolithic means.

Producing linseeds

Flax field and flax harvest

Flax field in august, ripe for harvesting. Photo: IAR project.
At harvesting on august 13th, the entire flax plants are pulled out by hand along with their roots. Photo: IAR project.

Removing capsules

The capsules can be removed by hand, with a comb or, like in the picture, very effectively with a bundle of sharpened rib bones. Photo: IAR project.
Most of the removed capsules still are complete. Photo: IAR project.


The flax capsules can be threshed very fast in a wooden mortar. Photo: IAR project.
The product of threshing is a mixture of linseeds and capsule fragments. These mixtures have been frequently found in neolithic wetland sites and give evidence of linseed production. Photo: IAR project.


For winnowing the flax capsules, a basket made of rush (Juncus species) and bast has been used. Photo: IAR project.
Winnowing separates linseeds from capsule fragments, because the latter are much more lighter and for that are carried away by the wind. Photo: IAR project.

Producing fibres

Flax retting

Freshly harvested flax has been laid on the field for retting. During the retting process the wooden parts of the stems break up and release the fibres. Photo: IAR project.
After one week the flax is getting brown. Photo: IAR project.
After four weeks in sun, wind and rain the flax has got a silver-grey colour, indicating that the retting-process is finished. Photo: IAR project.

Tenderising, breaking and heckling of flax

The rottened and dried flax stems have been tenderised with a wooden bludgeon. Photo: IAR project.
Between two logs of wood, the flax stems have been broken with the help of a wooden slasher. Short fragments of the wooden part of the stems (shives) are the by-product of this process. These have been frequently found in neolithic wetland sites. If occuring in large quantities, they give proof of flax fibre production at the site. Photo: IAR project.
Heckling has been carried out again with the help of a bundle of sharpened rib bones. The products of heckling are long flax fibres, the by-products are short, tangled fibres called tow or oacum. Photo: IAR project.

Tenderising, breaking and heckling of flax

From the long flax fibres, threads have been spun with a spindel whorl. Different types of spindle worls are common artefacts in neolithic wetland sites and point out, that spinning has performed. Photo: IAR project.
Fragment of a neolithic fish-net made of flax from the pile dwellings of Hornstaad, Germany. Photo: Landesamt für Denkmalpflege Baden-Württemberg.
Piece of a neolithic textile made of flax from the lake shore site of Wangen/Bodensee, Germany. Photo: Landesamt für Denkmalpflege Baden-Württemberg.


Pulses can be used at different stages of ripeness. In their green, unripe stage (for example "sugarpeas") the pods as well as the seeds are fresh, soft and pulpy and of a sweet taste. As they decay rapidly, they must be eaten soon and cannot be kept for a long period. If peas are picked at a ripe stage, the pods have developed a “parchment-layer”, a sclerenchymatic endocarp which makes them rather tough, hard and inedible. In that case the pods have to be removed from the seeds and are probably discarded as waste material or used as animal fodder. The ripe seeds are dry and hard and can be stored for longer. The pods found in the archaeological samples prove that the pulses were harvested at a ripe stage, when the sclerenchymatic endocarp had already been developed, and that these pulses may have been stored.

References among others:

  • Kenward & Hall 1995, fig. 191, p. 684,
  • Körber-Grohne 1967, 174ff., pl. 39-41,
  • Maier 2001, 73f.,
  • Maier 2004, 85.

Crab apple

How crab apples were processed in prehistoric times is shown by accumulations of charred apples found at waterlogged sites. Nearly all these apples have been cut in half and the skin of the fruits show that they must have been dried before charring. Probably these fruits were collected as a winter supply of Vitamin C and were destroyed accidentally during their preservation process.

References among others:

  • Gassner et al. 1989
  • Jacomet et al. 1989, 199f.
  • Kenward & Hall 1995, fig 191, p. 682
  • Maier 2001,
  • Maier 2004


Mistletoe has always been used as a ritual and magical plant as well as for medical purposes, but these uses can hardly be proved in the archaeobotanical material. However thick layers of epidermis fragments found at waterlogged sites, and the occurrence of remains in dung pellets show that at least in neolithic times the plant must have been used as a winter fodder for animals. The berries of mistletoe can also be used as a glue, for example to prepare glue traps for birds.

References among others:

  • Kühn, Hadorn 2004
  • Maier 2001, 135ff., 208
  • Zibulski 2004


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