Ok so I got impatient and decided to send my pic to any email address I could find on the Missouri website to try and get an answer...still didn't and will forward more pics to him if it ever stops raining here long enough in my effort for a real ID. The things we will do to get a name...Uggg
Your message and photo made its way to me. The flowers that you show do indeed look like a species of Strophostyles. The large banner petal (the top half of the flower), the twisted keel (the central portion of the flower), and the petal color (light pink fading to light yellow) are all characteristic of the genus. The genus also has a characteristc inflorescence in which the small cluster of lfowers is at the tip of a relatively long stalk, but that can't be seen from your image. Beyond that, I would need more information or to see more of the plant. There are two (of the three) Missouri species that have flowers similar to those you show. The easiest difference between them is that Strophostyles helvula has at least some of the leaves with the pair of lateral leaflets lobed (with a pair of shallow shoulders one one side toward the base or deeper lobes), whereas S. umbellata has all of the leaflets unlobed. I was at Creve Coeur County Park last week and Strophostyles helvula is very common there this year, especially along Little Creve Coeur Lake, which is the marsh that was cut off from the rest of the park by the Page Avenue Extension.