This name is a synonym of Penstemon angustifolius subsp. caudatus .
The record derives from Tropicos
(data supplied on )
which reports it as a synonym (record 50079706
) with original publication details: Minnesota Bot. Stud. 2(1): 34–35 1898.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:187256-2
.
This name was in version 1 of The Plant List, record tro-50079706.