Collected seeds and fruits from herbs as prehistoric food

New investigations of two archaeobotanical finds are presented: a large assemblage of pure fruits of Polygonum lapathifolium from Bremen-Strom, Germany and the gut contents of a bog body from Kayhausen near Oldenburg, Germany. The general question is to find out for sure which herb species were intentionally gathered for human consumption. To accept species as such, they have to fulfil mainly two criteria: they must occur in large and pure assemblages, separated from other species, and they should occur regularly in the stomach or gut of dead bodies. To ensure this, the data from all bog bodies whose intestines have been examined were compiled and in addition to this, fossil assemblages of the species in question were put together. It turned out that apart from gathering in the wild, the collection of seeds and fruits from weeds in the process of crop cleaning was a major source of their edible diaspores. Obviously some common weeds, obtained in this way, were welcome as an addition to human diet and received the status of secondary cultivated plants. The following six species are regarded as having surely been deliberately collected and used in human diet: Polygonum lapathifolium, Chenopodium album, Spergula arvensis, Fallopia convolvulus, Bromus secalinus and Glyceria fluitans. Another two, Setaria sp. and Rumex acetosella probably complete this list.