Notocactus megapotamicus var. flavispinus (Buining & Brederoo) W.R.Abraham & R.W.Buneker in Kakteen And. Sukk. 43(1): 21
Notocactus megapotamicus var. flavispinus in Kakteen And. Sukk. 43(1): 21. 1992
is new combination for Notocactus linkii var. flavispinus in Kakteen And. Sukk. 29: 27. 1978