The first part of the scientific name refers to the resemblance of the flowers to lips. I think I can sort of see this in the above photo. This species is a native of the SW U.S. and Mexico, so it is adapted for our dry climate here in west central Texas.
Desert Willow is widely cultivated and is commonly planted along the highways of west Texas.
Other interesting common names include Desert Catalpa and Flor De Mimbre. A member of the Boraginaceae plant family.
Texas Rolling Plains Naturalist 