Willow Springs, Arizona, by Dr. Palmer, are, by Mr. Watson, identified with this. Mr. H. H. Rusby obtained the same in flower only in a canyon of the San Francisco River in the same Territory, a few miles above the confluence of that stream with the Gila; but the material whence this description js drawn, was obtained by the writer in March and April of this year, at a locality still further east, namely, the canyon of the Upper Gila in Grant County, New Mexico, within fifteen miles of the dividing ridge between the Pacific and Atlantic slopes of the continent.