Green’s Dictionary of Slang

Columbine n.

[literary euph. Columbine, a character in Italian theatrical tradition commedia dell’arte, thence trad. pantomime, the mistress of Harlequin; the original columbine, a flower with ‘hollow horns’ is cited by Williams as a 16C image of cuckoldry]

a prostitute.

[UK]Barrère & Leland Dict. of Sl., Jargon and Cant.
[UK]Farmer & Henley Sl. and Its Analogues.