Marbled White on thistle

This was taken today on Old Winchester Hill during an outing organised by the local good folk from Butterfly Conservation.  It's the first marbled white butterfly I've been able to blip since the Wildlife Trust rather mistakenly (I thought) replaced some of the wildflowers on Winchester's Barton Farm with a row of shrubs.

I'm afraid in all the excitement I failed to identify the thistle.

We had a wonderful walk, slightly curtailed because of the heat, and I arrived home exhausted.  For that reason I intend to do most of my commenting tomorrow morning, if you don't mind.  I hope your Sunday's been a good one and that your week begins well  xx

PS:  Thanks to KatesGardenPDX I now believe this is a Spear Thistle