Fleur-de-lis

This is the chief among the heraldic flowers. It is the French royal emblem par excellence and was first borne on a royal seal by Louis VII in the 12th century, who on the anointing of his son, Philip Augustus, ordered that the young prince should be clad in a blue dalmatic and blue shoes, sewn with golden fleurs-de-lis, a flower whose name, as "Fleur de Loys", played upon that of his own, and possibly upon his epithet name of Florus. There is evidence however that its use dates  even further back to the Merovingians. Clovis and his successors bore a blue field covered with golden fleur-de-lis. Lily of the Flag was an ancient term for the fleur-de-lis as borne in the arms of France.

When used as a difference the fleur-de-lis represents the sixth son.

Dutch fleur-de-lis, as depicted by Dutch heralds.

Demi fleur-de-lis divided per pale.

Fleur-de-lis couped. 

Fleur-de-lis seeded. 

Semé-de-lis; Semé of fleur-de-lis indicates that the whole field, charge, supporter or crest is strewed over or powdered with fleur-de-lis.

Fleur-de-lis formed of three hues.