The folded leaves of Iris

But what's most interesting in the Iris is that the leaves are folded, with the two sides fused together into a seemingly simple structure. It's as if someone has taken a hot iron and pressed the whole clump of leaves into a flat sheet in preparation for mounting in a herbarium. You can see such leaves in many members of Iris, Gladiolus, and related genera. It has evolved independently in unrelated monocots such as Acorus (Acoraceae) and Lachnanthes (Haemodoraceae). Such folded leaves are...