In a systematic inventory in the cantons of Schaffhausen and Aargau (Switzerland), 111 findings of Buglossoides purpurocaerulea were noticed between 1968 and 1991. 88 vegetation releves were carried out in 1995/96. They belong to 6 associations or 9 forest communities according to Ellenberg and Klötzli. Buglossoides prefers warm, rather dry to relatively fresh sites on limestone or marl (Carici-Fagetum caricetosum montanae, Pulmonario-Fagetum melittetosum and Galio-Carpinetum primuletosum). Together with Buglossoides, a previously unknown occurrence of Sorbus domestica is reported near Villigen (Aargau). The occurrence of Buglossoides seems to be very persistent and not endangered by the actual forest management.