This name is a synonym of Diphyscium chiapense subsp. unipapillosum (Deguchi) T.Y. Chiang & S.H. Lin.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 35186474) with original publication details: Bryologist 93: 429. f. 1–5 1990.
This name was in version 1 of The Plant List, record tro-35186474, and has not been changed.