Sieving the weeds from the grains: an R based package for classifying archaeobotanical samples of cereals and pulses according to crop processing stages

The R package CropPro is an open-access resource to classify archaeobotanical samples as products and by-products of different stages of the crop processing sequence for large-seeded cereal and pulse crops in south west Asia, Europe and other Mediterranean regions. It builds on ethnographic research and analysis conducted by Jones (Plants and ancient man: studies in palaeoethnobotany. Balkema, Rotterdam, pp 43–61, 1984), (J Archaeol Sci 14:311–323, 1987), (Circaea 6:91–96, 1990) and a modified method by Charles (Environ Archaeol 1:111–122, 1998). CropPro provides functions, which allow users to construct triplots, to conduct discriminant analysis comparing archaeobotanical samples with ethnographic crop processing stages and to plot the discriminant analysis results. This paper provides two worked examples of the use of CropPro: the early medieval site of Stafford in the UK and the Bronze Age site of Tell Brak in Syria. These examples illustrate the use of the package for identifying crop-processing stages, and for assessing the relevance of taphonomic pathways other than crop processing.