Hesperocallidaceae was resurrected by Hamilton Traub in 1972 to contain a single genus and a single species Hesperocallis undulata. The APG II placed it into the Asparagaceae but allows it's reclassification into Hesperocallidaceae sensu Traub. The most recent taxonomic study using molecular data recommends its inclusion into Agavaceae. It is found in the dry deserts of Southwestern United States into Mexico.
We have the genus Hesperocallis represented on the wiki.