A very closely related weed is pale willow weed (Persicaria lapathifolia), which looks very similar to willow weed but the seed head is a paler pink, hence its name, often there is no blotch on the ...

Another oxalis species with pinkish flowers is lilac oxalis (Oxalis incarnata), but this has branched stems unlike pink shamrock and is more active in winter. Just to be very confusing, there is ...