Jill, I'm so glad that Malissa came out to help you. I became interested in Missouri natives in 1986. I was an hourly employee for MDC and a forester (now retired) was pretty knowledgeable about native plants which peaked my interest. I bought a copy of Denison's "Missouri Wildflowers" and became absolutely addicted. In 1987 I moved here and was able to observe a lot of plants in their natural setting. We have 40 acres in some pretty rugged Ozark deep draws and dry ridges. It's oak/hickory forests and is extremely rocky (car size boulders). I started growing natives and learning about seed collecting, etc. Over the years, we've noticed that our dry ridge with its accompanying draws has become more lush, the soil is better and the increase in species of birds is amazing. Along the way, I've had a lot of support from professionals at MDC. For the most part, these people are doing what they love and are dedicated to the resource. This forum is a great source of knowledge for natives. Somebody here knows the answer to about any question you might have. Keep in touch about your place and have fun!

Erodium.

Your plant is Centaurium tenuiflorum, which has sessile flowers. The other one in your area is C. pulchellum, with flowers on pedicels. The appearance can be misleading, because they sometimes look pedicellate, but aren't. That plant was relatively rare a few years ago, but is now found in southern AR in large, very attractive masses. If you must have a non-native, that one gets my vote.

Perhaps an Oxalis, maybe Oxalis violacea. I don’t know which would be common down your way. I also can’t clearly see to which leaf it attaches, or whether those are clover or oxalis leaves...