Abstract

This study records the first confirmed occurrence of Pluchea dioscoridis (Asteraceae) in the southern wetlands of Iraq, thereby extending the known geographic distribution of the species into the Mesopotamian marshland system. The identification was established through an integrated framework combining morphological assessment with nuclear DNA regions (Internal transcribed spacer and external transcribed spacer), ensuring accurate taxonomic placement. The principal component analysis of morphological traits shows that the first two components (PC1 = 30.58% and PC2 = 20.87%) explain over half of the total variation and reveal three major clusters. Phylogenetic analyses further demonstrated its close affinities with related Pluchea taxa, providing new molecular evidence that enriches the understanding of intrageneric relationships within the group. Beyond its floristic significance, this discovery provides valuable baseline data for biodiversity monitoring in Iraq’s marshes, a globally important yet understudied ecosystem. The occurrence and spread of P. dioscoridis in southern Iraq can be attributed to a combination of ecological conditions and human activities. This plant flourishes in damp environments such as river margins, irrigation ditches, and disturbed soils, all of which are widespread across the southern Iraqi plain. The records of this species highlight the importance of integrating classical botany with molecular systematics in exploring neglected habitats, while also underscoring the need for continued surveys to inform conservation and ecological restoration efforts in the region.

Key words: Iraq flora, ITS and ETS Markers, marsh habitats, and phylogenetic study