Reference:Crosswhite1965b
Revision as of 03:13, 29 July 2019 by Unknown user (talk)
Verbatim text: Crosswhite, F. S. 1965c. Subdivisions of Penstemon section Penstemon. Sida 2: 160–162.
Author: Crosswhite, F.S.
Year: 1965c
Title: Subdivisions of Penstemon section Penstemon
Volume: 2
Pages: 160–162