Okay
The Shepherd and Flora (No imprint slip, c1820)
As I went out walking one morning in May
When the fields were all green and were gay,
The trees and green bushes were covered with young,
And the small birds around me so joyfully sung. (7 stanzas)

The Unkind Shepherdess (Catnach, London, c1820-30)
I'll spread these green branches all over her young,
So well do I like my love so sweetly she sung,
Was there ever a young man in so happy a state,
As I with my Flora my Flora so great. (7 stanzas)

The Unkind Shepherdess (No imprint but very likely Kendrew of York c1810)
It was near a fountain where I sat alone,
The birds they sat round me to pitty my moan,
All drest in their branches and over me hung,
They seem'd to attend me so sweetly they sung. (7 stanzas)

And others with as much variation. Hardly recognisable as the same song from the first stanza and indeed the first 3 stanzas in each case. Not until the 4th stanza do they become recognisable as the same song. The pastoral style is very much that of the London theatres and pleasure gardens of the 18th century. For an early 19th century slip song to have so much variation between versions would probably put its composition back to at least c1750.

I'm pretty sure 'Flora, the Lily of the West' will be in the DT. Try it on the search engine at the top of the home page.