Abstract
Oenanthe incrassans (Apiaceae) was discovered in Istanbul, Turkey. It is related to Oenanthe pimpinelloides, but it clearly differs in terms of leaves, inflorescence (ray, bracts, and bracteoles) and fruit features. A taxonomic description, some photographs of the species, geographical distribution and habitat features are given. Additionally, fruit micromorphology, stem, ray and fruit anatomy, and pollen features are studied for the first time and compared to Oenanthe pimpinelloides.