So when are you going to start giving photography lessons?

When you have two different forms of a Till. are the flowers supposed to stay consistent with just a change in foliage? Those petals look completely different to my untrained eye.

Hmmm...apart from Mike's comment about the petal shapes differing, is there also a difference with the throat and/or stigma colour? - yellow throat on left, and same colour throat as petals on the one on right. The larger, more open-shaped petal one (on right in first pic) also appears to have fewer flower segments, the sepals look more pointy in its inflorescence. They also appear to be arranged differently. The left one's inflo appears to be a fan shape, versus the right one more of an alternate branching...

Nit-picking here - but you asked, Gonz!

K

A change in petal shape could be caused by anything, I don't think anybody knows why those things happen. But, welcome to the age of the new genus Sequencia! Soon enough, somebody from Wisconsin (or where ever) will be able to answer your questions.