⚠ Version 1 of The Plant List has been superseded.

This name is in version 1.1 of The Plant List, record tro-50100371, with some changes.

Zanthoxylum williamii (Albuq.) P.G. Waterman is a synonym of Zanthoxylum riedelianum Engl.

This name is a synonym of Zanthoxylum riedelianum Engl..

The record derives from Tropicos which reports it as a synonym (record 50100371) with original publication details: Taxon 24: 365 365 1975.

Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:270818-2.