Fern, form and function
Why stem and rachis, root and rhizome, and leaves and pinnae, I cannot say. No matter nomenclature, I appreciate the rachis for its lazy arch, the graceful elegance of pinnae, and the feel of stored potential expressed in the crozier. This plant will release spores that will germinate and give rise to one that looks quite different. When mature, the gametophyte will release egg and sperm which fuse to then develop into the familiar frond once again. To what end? I cannot say.