⚠ Version 1 of The Plant List has been superseded.

This name is in version 1.1 of The Plant List, record tro-35164173, with some changes.

Hydrogonium williamsii P.C. Chen is a synonym of Barbula williamsii (P.C. Chen) Z. Iwats. & B.C. Tan

This name is a synonym of Barbula williamsii (P.C. Chen) Z. Iwats. & B.C. Tan.

The record derives from Tropicos which reports it as a synonym (record 35164173) with original publication details: Hedwigia 80: 239. pl. 44: f. 6--9 239 1941.