Kipp and Stephen. I am growing H crispus here in Melbourne, Australia and climatic conditions aside, I think what you have highlighted Kipp with the linked picture you posted is just how much variability there is in the wild in not only this species but just about every plant species. I have a mature plant and a number of young seedlings of which there is quite some variability - some undulate and some not. I am told the undulation develops as they mature. The mature plant is quite green and undulate in leaf with spotting near the base. The leaves are quite slender at only approximately 15mm wide by approximately 250mm long. The specimens in Kipp's link are quite glaucous, appear to be somewhat broader and have no spotting. It would certainly be a nice form to get hold of! If I could figure out how to get a photo up I would show you all the difference!