Dear Randy,
I am so sure which structure you are referring to. When I look at sunspots in the detailed data from our ground-based and space based observatories, they remind me of sunflowers. The inner darkest part shows almost no strucutre, and it can be compared with the center of the sunflower, while the outer ring of the sunspot displays a structure akin to the petals of a sunflower. Outside of the sunspot, many data sets show the granulation on the surface of the sun, which are columns of hotter and colder gas moving vertically, creating this ring-like structure.
Isabel Hawkins