From seeds of Aesculus hippocastanum, Clitoria ternatea, Dahlia merckii and Heuchera sanguinea five antifungal proteins were isolated and shown to be homologous to plant defensins previously characterised from radish seeds and gamma-thionins from Poaceae seeds. Based on the spectrum of their antimicrobial activity and the morphological distortions they induce on fungi the peptides can be divided into two classes. The peptides did not inhibit any of three different alpha-amylases.