⚠ Version 1 of The Plant List has been superseded.

This name is in version 1.1 of The Plant List, record tro-5108440, with some changes.

Mammillaria nuttallii var. robustior (Engelm.) Engelm. & Bigelow is a synonym of Escobaria missouriensis (Sweet) D.R.Hunt

This name is a synonym of Escobaria missouriensis (Sweet) D.R.Hunt.

The record derives from Tropicos which reports it as a synonym (record 5108440) with original publication details: Pacif. Railr. Rep. 4: 28 28 1856.