E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
The fruit was originally white, and became blood-red from the blood of Pyramus and Thisb. The tale is, that Thisb was to meet her lover at the white mulberry-tree near the tomb of Ninus, in a suburb of Babylon. Being scared by a lion, Thisb fled, and, dropping her veil, it was besmeared with blood. Pyramus, thinking his lady-love had been devoured by a lion, slew himself, and Thisb, coming up soon afterwards, stabbed herself also. The blood of the lovers stained the white fruit of the mulberry-tree into its present colour.
The botanical name is Morus, from the Greek moros (a fool); so called, we are told in the Hortus Anglicus, because it is reputed the wisest of all flowers, as it never buds till the cold weather is past and gone.
In the Seven Champions (pt. i. chap. iv.) we are told that Eglantine, daughter of the King of Thessaly, was transformed into a mulberry-tree.