Molecular phylogenetic data: DNA sequences and tree files: Medicago_ITS_2025_07_07.fasta Medicago_ITS_2025_07_07.fasta.iqtree Medicago_ITS_2025_07_07.fasta.treefile.tre medicago_matK_2025_07_07.fasta medicago_matK_2025_07_07.fasta.iqtree medicago_matK_2025_07_07.fasta.treefile.tre Medicato_GA3ox1_2025_07_07.fasta Medicato_GA3ox1_2025_07_07.fasta.iqtree Medicato_GA3ox1_2025_07_07.fasta.treefile.tre

A new species of Medicago, Medicago peregrina, is described, supported by a unique combination of morphological characteristics and phylogenetic evidence derived from nuclear ITS and GA3ox1 markers, as well as plastid matK sequences. A single individual of this species was discovered in 2022 on a disturbed bank of the Vesdre River in Goffontaine, Belgium, following the major flood of the previous year. It is clearly non-native to Belgium and is almost certainly linked to historical wool processing activities in the valley. Based on the geographic origins of imported wool and the inferred genetic affinities of the new taxon, its native range likely lies in the Middle East—though the species has not yet been documented from that region. This discovery illustrates how historical trade can leave transient botanical traces and emphasizes the importance of continued botanical surveys in disturbed habitats.