This name is a synonym of Amaranthus tuberculatus (Moq.) Sauer.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50085840) with original publication details: Rhodora 10(110): 32 1908.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:3294-2.
This name was in version 1 of The Plant List, record tro-50085840, and has not been changed.