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 1101088) with original publication details: Rhodora 43: 288 1941.
This name was in version 1 of The Plant List, record tro-1101088, and has not been changed.