The filling of two octagonal basins of a Roman Apollo Grannus sanctuary at Neuenstadt am Kocher, Baden-Württemberg contained wet preserved organic matter in high concentration. Plant macrofossils and pollen were studied. The only evidences for cultivated agricultural plants were cereal pollen and fruits as well as pollen of Cannabis sativa. Other cultivated plants are Apium graveolens and Rheum rhabarbarum, documented by pollen, as well as a fruit of Piper nigrum, the latter a rather surprising find. Common were edible plants gathered in the wild, as Humulus lupulus and several fruits. In general, a more or less semi-open landscape with forest, shrubland, and agricultural land is indicated. According to a coin and radiocarbon dates the basins were not filled-up in the Roman period, when the sanctuary was in use, but afterwards, when the Roman border was shifted back to the Upper Rhein and this region was occupied by Alamannic tribes. The filling of the basin was therefore most probably caused by those people, and it is rather surprising that they obviously had Piper nigrum.