The first of May in France is a public holiday to celebrate workers rights. It is La Fête du Travail (Labor day).
It is also an occasion to offer loved ones a little brin de muguet (sprig of lily of the valley). These flowers are sold everywhere even on the street around France. People give them to friends or family members for good luck.
Offering a little muguet in spring was common in mediaeval times. However, it seems that it became officialised on May 1st, 1561 when King Charles IX, having received a sprig himself, decided to present lily of the valley flowers to the ladies of his court each year. From then on, the tradition continued.
In more recent history it became linked to the worker’s rights movement after demonstrators wore du muguet during their marches. Demonstrating workers used to wear the red triangle in their buttonholes to symbolise the ideal division of the day into three equal parts: 8 hours of work, 8 hours of rest and 8 hours of leisure. Later this red triangle was replaced by the wild rose and then by the lily of the valley.
According to Le Figaro, over 60 million brins de muguet are sold in France every year, representing an official market of around €24 million, and taking into account street vendors the unofficial figure is four times as high.