He specialized in lichenology and plant geography. She published on bryology, lichenology and vascular plants. Scholars of lichenology are known as lichenologists. Throughout his career he had a passion for botany, especially lichenology. In retirement, he continued his studies in the field of lichenology. The Acharius Medal is awarded for lifetime achievement in lichenology. She then completed a PhD in lichenology (1968) in the Institute of Botany Jagiellonian University. In 1992, Trass was awarded the Acharius Medal by the International Association for Lichenology. In 2002, he was honoured with an Acharius Medal by the International Association for Lichenology.