Lily of the Valley especially for my French friends -- Vagabonde, Therese, and Miss Yves. (I'm told that sending lily of the valley on May Day is traditional in France.)
Once it was the custom to leave a basket of flowers hanging from your neighbor's door knob (see HERE) -- a charming tradition that has pretty much gone now -- along with the Maypole.
So consider these blossoms your virtual May basket.
You'll have to imagine the Maypole. Or watch THIS.