Hypericum pauciflorum Kunth
A primarily Mexican species with bluish glaucous leaves, entering the United States only in extreme southern Texas.
Plant habit at Valle de los Monjes, near Creel, Chihuahua, Mexico, 7 Sep 2009. Photographed on a field trip with the American Penstemon Society.
A flower, cropped from the above photo, 7 Sep 2009.