Booklist Books and General Publications of Interest to Penstemaniacs
For an especially thorough bibliography that includes the select best of periodical and journallistings of interest go to The Penstemon Website" maintained by Andrea Wolfe.
Rather than to duplicate Andrea's fine accomplishment the main purpose of this FAQ (Acronym that stands for Frequently Asked Question) is to acquaint Penstemon-L list members with some general and "benchmark" books available. Thus the emphasis here will be on maintaining a short list in informal bibliographic style of select penstemon books and more general references that include penstemon or related genera. There will only be enough overlap in the two bibliographies to serve as an orientation.
GENERAL REFERENCES
PENSTEMON BOOKS AND KEYS