This name is a synonym of Equisetum × nelsonii (A.A. Eaton) J.H. Schaffn..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 26604574) with original publication details: Fern Bull. 12: 41 1904.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:93037-2.
This name was in version 1 of The Plant List, record tro-26604574.