The current paper constitutes an attempt to identify the algae, fungi, lichens and liverworts mentioned in the extensive Herbal by Syreniusz, published in Cracow in 1613. All four algae mentioned are maritime species. As for fungi, Syreniusz described the fungus Fomitopsis officinalis, which was then used in medicine, and he listed several Polish names of edible and poisonous macromycetes, and also mentioned rust on wheat. The lichen that has been identified is the species Lobaria pulmonaria, and the liverwort is Marchantia polymorpha, both used in medicine.