This member of the Evening Primrose Family is a very close look-alike to some Oenotheras but the latter bloom in the evening and begin withering early in the morning whereas Calylophus lavandulifolia blooms during the day. The long trumpet-like flowers (see left center of the photograph) dry to shades of pink-orange-rust.  Leaves are short and narrow with smooth edges.

"Caly" is Greek for "calyx" and "lophus" is Greek for "a crest", both referring to a small projection from the sepals.  "Lavandulifolia" refers to the lavender-like leaves.

The first specimen of this plant was collected for science by Edwin James near the Platte in Colorado in 1820 and the plant was named Oenothera lavandulaefolia by Torrey and Gray in 1840; it was renamed Calylophus lavandulifolia by Peter Raven in 1964.