Reference:Crosswhite1967b
Verbatim text: Crosswhite, F. S. 1967b. Revision of Penstemon section Habroanthus (Scrophulariaceae) II: Series Speciosi. Amer. Midl. Naturalist 77: 12–27.
Author: Crosswhite, F.S.
Year: 1967b
Title: Revision of Penstemon section Habroanthus (Scrophulariaceae) II: Series Speciosi
Journal: Amer. Midl. Naturalist
Volume: 77
Pages: 12–27