This member of the Euphorbiaceae family was given this name by Ira Loren Wiggins and Reed Clark Rollins in 1943. It is found in dry areas of the Sonora Desert and Baja Norte in Mexico and Arizona in North America, growing in a well drained soil with some water and some to lots of sun. The swollen root can grow to twelve centimetres or more, the entire bush can reach two metres in height. The flowers are white to pale yellow.
The genera name from the Greek words ἰατρός; iatros, meaning 'physician', and τροφή; trophe meaning 'nutrition', as to medicinal uses. The species name means 'pointed, wedge-shaped'. A wild plant from Cabezaprieta.org.

