Verbatim text: Keck, D. D. 1932. Studies in Penstemon. A systematic treatment of section Saccanthera. Univ. Calif. Publ. Bot. 16: 367–426.
Author: Keck, D.D.
Year: 1932
Title: Studies in Penstemon. A systematic treatment of section Saccanthera
Journal: Univ. Calif. Publ. Bot
Volume: 16
Pages: 367–426