This name is a synonym of Amaranthus tuberculatus (Moq.) Sauer.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Amer. Midl. Naturalist 4: 308 1916.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:3293-2.
This name was in version 1 of The Plant List, record kew-2618233, and has not been changed.