The green cockade is a Cornish version of a song more widely known as The white cockade; in other versions it’s blue. I dare say it depends who was recruiting in the area at the time. The Cornish version says less than some about the actual recruiting, focusing mainly on the loss and heartbreak angle.
This is another song I’d vaguely known for a while, but which I never rated particularly highly until I heard Jo Freya’s beautifully realised version. There’s concertina here too, and this time I did work out the chords.