The remains of black henbane (Hyoscyamus niger) are relatively common at archaeological sites as it grows naturally around settlements in north-western Europe. All parts of the plant may be used as a medicine or a narcotic but its natural prevalence in built environments makes it difficult to interpret any intentionality behind its presence in the archaeological record. Evidence of the deliberate collection and use of black henbane seeds in the Roman Netherlands is presented here for the first time. Examination of Classical texts and interrogation of the archaeobotanical data allow the authors to place the discovery at Houten-Castellum of a hollowed bone containing hundreds of black henbane seeds within the context of the wider Roman understanding of the plant and its properties.

Birch-bark tar, used continuously in the territory of modern Europe from the Middle Palaeolithic to the Iron Age, is conspicuous by its absence in the archaeological record of the Roman period, suggesting its replacement by conifer-based products. The results of chemical analyses of residues on Roman hinges, however, now challenge this interpretation. The presence of birch-bark tar in most of the samples demonstrates the persistence of a long-established practice into the Roman period. Examined in relation to textual and environmental evidence, these results illuminate the transmission of technical knowledge and the development of long-distance trade networks associated with birch-bark tar.

The authors discuss the first evidence for the use of birch-bark tar on Late Neolithic pottery from Greece. This appears to have been used for two different purposes, to seal a fracture and to line the interior walls. The authors also discuss other possible uses.