This name is a synonym of Ophioglossum nudicaule var. robustum Licht..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26604264) with original publication details: Filic. Afr. 28: 23 1953.
This name was in version 1 of The Plant List, record tro-26604264, and has not been changed.