Heuchera sanguinea

While this is often described as a southern Arizona species, perhaps 90% of its range is in Mexico, and there are peripheral occurrences in adjacent New Mexico. Heuchera sanguinea has been cultivated since the 19th century and is figured in Curtis' Botanical Magazine (where the rest of the genus is referred to as largely "unpretentious"). It is often strongly variegated; the depth of the cerise color is also variable. Completely white horticultural forms are known. In nature usually the inner hypanthium surface is white -- a differentially pigmented internal hypanthium is apparently unique to this species.

These photos come from a cultivated plant originally collected in the Dragoon Mountains, AZ. It was sent to me as a particularly dark form.