This name is a synonym of Adiantum melanoleucum var. nanum (Jenman) Jenman.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26622574) with original publication details: J. Bot. 17: 258 1879.
This name was in version 1 of The Plant List, record tro-26622574.