As far back as the time of Pliny, the water-lily was regarded as an antidote to the love-philtre, and the amaranth was used for curbing the affections.

On the other hand, Our Lady's bedstraw and the mallow were supposed to have the reverse effect, while the myrtle not only created love, but preserved it.

The Sicilians still employ hemp to secure the affections of those they love, and gather it with various formalities,[2] fully believing in its potency.

Indeed, charms of this kind are found throughout the world, every country having its own special plants in demand for this purpose.
However whimsical they may seem, they at any rate have the sanction of antiquity, and can claim an antecedent history certainly worthy of a better cause.
Footnotes: 1.

Thorpe's "Northern Mythology." 2.