I've heard a lot about black brush (Coleogyne ramosissima) but I'm not sure I've ever seen it, though every time I see rhatany (Krameria grayii) I think this must be it as the stems are so black and dead looking. But I've learned that this is rhatany.
The fact that there's a creosote (Larrea tridentata) growing out of the center of these verifies that I've made the right ID as rhatany is a parasite on creosote. You can see the yellow green branch of creosote growing out of the top left hand bush. I know in the spring this plant has the most beautiful purple flowers. I've seen them in the monument. The root is used in herbal medicines.
I'm embarrassed to say I may not be able to tell a true black brush from a creosote and in the spring will make a point to count the petals on the blossoms that each plants bears. The creosote has five petals while black brush has only four.