I hadn't heard of it (probably because it doesn't grow out here east of the Mississippi), but it is a native variety of cleome. Very pretty!
Here's a couple interesting articles about the plant and its uses. Seeds and leaves are edible.
The seeds have a relatively low germination rate and it helps to moist stratify them before planting (put it between damp paper towels in a ziplock baggie for a few days). Like other cleomes, these seeds need temp variation between day and night to germinate, so easier to do outdoors than in. They may take a couple weeks to germinate, so be patient.