Also known as Sulfur flower and Buckwheat, Eriogonum umbellatum is one of my favorite native plants of Wyoming. It consists of a ground cover of small ovate leaves 4 inches high and topped with flower stems 8-10 inches tall. In my gardens it has grown to cover a 24 inch circular patch. In Wyoming we have four varieties.*
In the photos you can see the most obvious distinction between varieties is the flower color. Eriogonum umbellatum var. umbellatum and aureum have bright yellow flowers. I think the one in the photo is variety aureum.
Eriogonum umbellatum var. dichrocephalum and majus have beautiful creamy flowers. The one in my area has a white cast on the leaf undersides. The blooms turn a beautiful rosy color as they mature and dry.
I have collected seed from this plant and plan to use it in my sandy yard in full sun.
*Dorn, R.D. 2001. Vascular Plants of Wyoming