(Ignoring the tiresome ongoing Clash of the Titans...)

Regarding the symbolism in this song, I always took the bunch of thyme to represent Virginity, although rosemary is often used to represent this, particularly with regard to the Virgin Mary.

The 'lusty sailor who gave to her a rose, a rose which never would decay' was a flowery way of saying he infected her with a sexually transmitted disease (syphilis?)

In the song 'Will Ye Go Lassie Go?' the lad suggests they go off to pick wild mountain thyme, which I used to assume amounted to much the same thing (taking her virginity)

It amuses me when even today, young women refer coyly to their 'lady garden'.