E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
If you look at a leaf of myrtle in a strong light, you will see that it is pierced with innumerable little punctures. According to fable, Phædra, wife of Theseus, fell in love with Hippolotus, her step-son; and when Hippolotus went to the arena to exercise his horses, Phædra repaired to a myrtle-tree in Trzen to await his return, and beguiled the time by piercing the leaves with a hair-pin. The punctures referred to are an abiding memento of this tradition.
In the Orlando Furioso Astolpho is changed into a myrtle-tree by Acrisia.
Myrtle. The ancient Jews believed that the eating of myrtle leaves conferred the power of detecting witches; and it was a superstition that if the leaves crackled in the hands the person beloved would prove faithful.
The myrtle which dropped blood. Ænas (book iii.) is represented as tearing up the Myrtle which dropped blood. Polydorus tells us that the barbarous inhabitants of the country pierced the Myrtle (then a living being) with spears and arrows. The body of the Myrtle took root and grew into the bleeding tree.