I think this one might be C. clivicola, which shows in the nearby sightings. C. cornuta buds are 'plumper' looking and the stem (which is surrounded by the leaf all the way up) looks thicker and greener than this. If you could find this plant again, it would be interesting to check.
Thanks Cath. I do remember being a bit unsure about this one. I initially confirmed on the basis of the leaf ending just below the flowers. Looking at the image again I think the "leaf" may just be a change in colour on the stem rather than a leaf.
This is correct - I have actually kept an eye on this one and it turned into C. clivicola although an unusual colouring. It is surrounded by half a dozen C. cornuta which is why I assumed it would turn into one; I was initially mostly focused on the early flowering.