Trifolium dubium, the lesser trefoil, lesser hop trefoil or suckling clover is a plant in the family Fabaceae. This species is generally accepted as the primary plant to represent the traditional Irish shamrock.It is native to Europe, but can be found in many parts of the world as an introduced species.It is probably an allotetraploid that arose from the crossing of Trifolium campestre and T. micranthum.