A new searchable database of l phytoliths images has been made available by the Barcelona lab GEPEG (Research Group for Palaeocological and Geoarchaeological Studies). Find it here: GEPEG phytolith database. I have not had a chance to explore it in detail, but it will doubtless prove useful. It has about 185 images in it, so it by no means comprehensive, and it includes archaeological as well as modern reference material. (And it reminds me that our UCL phytolith on-line gallery needs updating, as I have let in languish for a few years without additions).
Friday, 28 October 2011
Monday, 10 October 2011
Experimental approaches to understanding variation in grain size in Panicum miliaceum" in Vegetation History and Archaeobotany. One of the major conclusions is that immature grains are likely to preserve archaeologically and contribute small grains to samples, and their recognition is important for archaeobotanical interpretation. This study vindicates the recognition and quantification of immature millet grains, indeed both immature Setaria italica and Panicum miliaceum have been recognized and reported from recent work in China (starting from Fuller and Zhang (2007)'s report on Ying valley survey samples [pdf from here], although it did not provide adequate illustrations). Immature grains have often is overlooked or lumped with other small grasses, such as Digitaria sp. as indeterminate "panicoids". Examples can be found in illustrated reports, such as the the two at the right, in which the modern grain at the top is a 8-day-old grain from the new Motuzaite-Matuzeviciute paper and the other two are from Huizui and the Yiluo reports (published by Lee et al in Indo-Pacific Prehistory Bulletin and PNAS in 2007). I do not mean here to single out any lab as worse than any other, all or most archaeobotanists were failing to deal adequately with highly immature millet grains-- indeed I suspect I need to go back through samples from Neolithic South India sorted during my PhD to check for mis-counted immature Brachiaria ramosa grains. The important thing is for practice to change. Immature grains are important for the recognition of crop-processing stages in millets (as discussed in Fuller and Zhang 2007). In addition, a shift from more to less immature grains harvested might be expected to take place with domestication, much as was the case with rice, i.e. morphologically wild panicles needed to be targeted on average more green to avoid grain loss to shattering. (This issue I raised in relation to rice domestication a few years ago, for example in Antiquity 2007).