This is not the Wild Mountain Thyme, Mick, but Tannahill's song.

The Braes o' Balquhither, A Scotch, Song Air .. The Three Carls o' Buchanan

Let us go,Lassie go,
To the braes o' Balquhither.
Where the blae berries grow
'Mang the bonnie highland heather;
Where the deer and the rae.
Lightly bounding together,
Sport the lang simmer day
On the braes o' Balquhither.

I will twine thee a bow'r,
By the clear siller fountain,
And I'll cover it o'er,
Wi' the flow rs o' the mountain;
I'll range thro' the wilds,
And the steep glens sae dreary,
And return wi' their Spoils,
To the bow'r o' my dearie.

While the Lads o' the South,
Toil for bare war'ly treasure,
To the Lads o' the North,
Ev'ry day brings its pleasure;
Tho Simple are the joys,
The brave Highlander possesses,
Yet he feels no annoys,
For he fears no distresses.

When the rude wintry win',
Idly raves round his dwelling,
And the roar of the linn,
On the night-breeze is swelling;
Then so merrily he'll sing,
As the storm rattles o're him,
'Till the dear Sheeling ring,
Wi' the light lilting Jorum.

Now the Simmer is in prime,
Wi' the flow'rs richly blooming,
And the wild mountain thyme,
A' the moorlands perfuming;
To our dear native Scenes,
Let us journey together,
Where glad innocence reigns,
'Mang the braes o' Balquhither.

The spelling is exactly as written by Tannahill. He wrote this in 'Paisley' English where only the odd word is Scottish as in 'simmer', 'siller', 'lang, 'bonnie'. It was Semple in the Centenary edition of Tannahill's works who suggested maybe 'lightly' should be written as 'lichtly' etcetera. But the rhyme is pretty strict ACBD and I'm constantly surprised when singers choose to Scotify certain words and pronounce 'grow' as in 'now' where it stands out like a sore thumb against 'go'. McColl did this, copying his mother, and a few singers have copied him.The same applies to singing 'roe' instead of 'rae' as Tannahill wrote. 'Floo'ers' does not rhyhme with 'bow'rs'. I suggest reading Tannahill's original in 'English' and your ear will do the rest. The melody is an other story entirely and I'm currently researching the two airs associated with Tannahill's lyrics.