Medicago arborea is a plant species of the genus Medicago.
Common names include moon trefoil, shrub medick, alfalfa
arborea, and tree medick. It is found throughout Europe and
especially in the Mediterranean basin, primarily on rocky shores among shrubby
vegetation. It forms a symbiotic relationship with the bacterium Sinorhizobium meliloti, which is capable of
nitrogen fixation. It is the only member of the
genus Medicago which is used as an ornamental. M. arborea is
sometimes misidentified as Cytisus, which it resembles.