Actually, the picture wildflower shows is a perfect example of sepals, but your's, jmorth, is not. (But it really is a nice pic!) What you have, is an umbel of many individual flowers. Each individual flower would have sepals. A collective bunch of flowers never does. Each of your red flowers has an ovary (where seed would be produced), as indicated by the blue arrows below:
If these red flowers have sepals, they would be located just below the petals, and in this case, above the ovaries. Sepals take many forms and in fact may look just like petals, and I cannot tell positively if the flowers have sepals or not. But the whorl of green at the convergence of individual flower stems are a sort of modified leaves, probably termed as bracts.
Edited for grammar.
