This name is a synonym of Isoetes karstenii var. anomala (T.C. Palmer) R.L. Small & Hickey.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50064833) with original publication details: Proc. Kon. Ned. Akad. Wetensch., C 85: 226 1982.
This name was in version 1 of The Plant List, record tro-50064833, and has not been changed.