One like 'Gravetye Beauty'. To see a range of cultivars in the right group do an image search for Clematis texensis.
That was helpful. Most of the C. texensis photos I clicked on that looked similar turned out to be 'Princess Diana' or 'Duchess of Albany'. None of those names are on our inventory list. They're very pretty flowers.
I recall a planting at the garden labeled C. texensis. If my recollection is correct* and this is the same (or a similar) accession maybe somebody on the staff noticed the specimen shown was instead a garden form and removed the label. *Due to not wanting to bother with the tightening of the border crossing I haven't been up there in years
