Foothill Penstemon

Bonnie’s cover for this Obispoensis was used for a banquet program cover back in 1984. We have no record of it ever being used as a newsletter cover. We would welcome a note form anyone who might remember it ( or 543-7051). You might notice something else about the appearance of the drawing. It has much more fine detail than Bonnie’s drawings used in Dr. Keil’s and my textbook or more recent newsletters. This is because it was done to size (3½ x 3½ inches) using fine drawing pens. It was not drawn to be reduced or enlarged. Bonnie’s more recent drawings are done with in less detail because they are meant to be reduced. Also, Dirk encourages simple drawings that distill the plant down to basic characteristics.

The plant is P. heterophyllus (or Penstemon heterophylla) depending on which flower book is used. I’ve seen both in the literature. The most recent Jepson Manual uses the name, P. heterophyllus. The correct ending depends on whether one considers the genus name, Penstemon, to be masculine or feminine or neuter. Of course, in reality, it is both as the flowers contain both male stamens and a female pistil. But in Latin, which all scientific names are considered, almost everything has to be assigned a gender whether it was appropriate or not. Second, in Latin, an adjective usually has the very same ending as the noun it modifies. For example, the scientific name for our common black sage is Salvia mellifera. However, following Latin rules can create exceptions. The most common one is with trees.

Trees were considered by the Romans to be feminine. Therefore the masculine noun for the oaks is Quercus but the adjectives that make up its specific epithet must be feminine. So we get the scientific name for the coast live oak, Quercus agrifolia. The other exception is when the noun or the adjective is irregular. When this occurs, one almost just has to memorize the endings since rules don’t seem to work. At least, I haven’t been able to make consistent sense out of them.

I’ve found two common names for this plant. They are foothill penstemon and blue bedder penstemon. The former name refers to it habitat or range. It is widespread in the interior foothills up to over 5,000 feet (1700 m) throughout much of interior California.

I’ve observed it to be particularly common in the mountains behind Santa Barbara and in the Sierra Nevada. (We should see much of it on the President’s Trip this coming June 16-17.) I’ve found it to be quite variable in flower color. Most of the time it is a bright bluish pink color, but it can be pinkish blue or even completely blue. Its habit is to branch profusely with its branches lying flat until they turn up at the tips.

Note Bonnie’s habit sketch. This habit would make it an excellent plant to fill in a flower bed, thus the latter common name, bedder penstemon. Although blue flower color is less common than pink, many of the pictures of this plant I saw on the Web were of plants bearing large, dark blue flowers. I interpret this observation to mean that what are being put on the Web are garden plants selected for their larger size and bluer colored flowers. Since the plant is commonly found on disturbed edges of roads and paths or where vegetation is scattered, I suspect it should readily adapt to the organized disturbance we call gardening. Oh, most important, the most easily recognized character of this species is its YELLOW BUDS!

Lastly, I haven’t mentioned the family to which this plant belongs. If you think it is obviously in the figwort family you would be behind the times. It seems that a number of species were hiding in this family. Recent taxonomic work using newly discovered tools of DNA sequencing and sophisticated computer based comparison methods discovered their deceit. Before the availability of these modern tools, taxonomists depended on characters that were relatively “visible” to the naked eye or simple microscopic and biochemical characters. Similarity was determined by the taxonomist’s gestalt and/or with the help of relatively simple computer programs that assess similarity.

One obvious character that separated the old Scrophulariaceae from the old Plantaginaceae (plantains) was the size of their flowers. Plantains had very tiny, tightly clustered flowers so that casual observers would often not even know they were in full bloom when they were. In contrast, almost all the old Scrophulariaceae had large, readily visible flowers. So, seemingly it was easy to tell the two families apart. But, if one got out the microscope and examined the tiny flowers in the plantain family, one discovered that they were, in fact, just tiny figwort flowers. This became clearer when the newer computer analysis determined that most of the genera of these two families fell out in same cluster, i.e., they were more similar to each other than they were to the few genera left in Scrophulariaceae – e.g. figwort, Scrophularia. So, beautiful, large-flowered foothill penstemon was transferred to its rightful place in the formally all small-flowered Plantaginaceae.

by Dirk Walters, illustrations by Bonnie Walters | Dirk and Bonnie Walters are long-time CNPS-SLO members, contributors, and board/committee participants. In addition to his work at Cal Poly, Dirk is the current CNPS-SLO Historian.