Technical Abstract: Extracts from thirty plants of the Greek flora were evaluated for their antifungal activity using direct-bioautography assays with three Colletotrichum species. Among the bioactive extracts, the dichloromethane extract of the radix of Echinops ritro was the most potent. Bioassay-guided fractionation of this extract led to the isolation of eight thiophenes. Antifungal activities of isolated compounds together with a previously isolated thiophene from E. transiliensis were first evaluated by bioautography and subsequently evaluated in greater detail using a 96-well microtiter assay against Colletotrichum acutatum, C. fragariae, C. gloeosporioides, Botrytis cinerea, Fusarium oxysporum, Phomopsis viticola, and P. obscurans. 5'-(3-buten-1-ynyl)-2,2'-bithiophen (1), alpha-terthienyl (2) and 2-[pent-1,3-diynyl]-5[4-hydroxybut-1-ynyl]-thiophene (5) at 3 and 30 uM were active against all three Colletotrichum species, Fusarium oxysporum, Phomopsis viticola, and P. obscurans.