Discovered far from home: a new Medicago species (Fabaceae) of unknown origin, associated with historical wool imports in Belgium

Sequences alignemnts of nuclear rDNA internal transcribed spacer (ITS), GA3ox gene, and the plastid-encoded trnK intron-matK gene region (matK). 

Results of the IQTREE phylogenetic analysis.

Abstract: 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.