⚠ Version 1 of The Plant List has been superseded.
This name record (from Tropicos) is not included in version 1.1 of The Plant List. It is possible the same name is included from a different data source, to check this you can search for Melocactus ruestii in version 1.1 of The Plant List.
This name is a synonym of Melocactus curvispinus subsp. curvispinus .
The record derives from Tropicos which reports it as a synonym (record 5107973
) with original publication details: Cact. Suc. Mex. 31(3): 53-54 53 1986.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:280717-2
.