⚠ Version 1 of The Plant List has been superseded.
This name is in version 1.1 of The Plant List, record tro-29204314, with some changes.
This name is a synonym of Penstemon palmeri var. macranthus (Eastw.) N.H. Holmgren.
The record derives from Tropicos which reports it as a synonym (record 29204314) with original publication details: Bull. Torrey Bot. Club 32(4): 207 207 1905.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:187470-2.