shamrock (n.)creeping European clover having white to pink flowers and bright green leaves; naturalized in United States; widely grown for forage;
Synonyms: white clover / dutch clover / Trifolium repens
shamrock (n.)Eurasian plant with heart-shaped trifoliate leaves and white purple-veined flowers;
Synonyms: common wood sorrel / cuckoo bread / Oxalis acetosella
shamrock (n.)clover native to Ireland with yellowish flowers; often considered the true or original shamrock;
Synonyms: hop clover / lesser yellow trefoil / Trifolium dubium